Apparatus for Producing sterilized water

ABSTRACT

There is provided an apparatus for manufacturing sterilizing water, in which the sterilization power of a chlorine-based solution consisting of sodium hypochlorite or chlorine dioxide or a mixture thereof is fully achieved while the generation of chlorine gas is restrained, and desired sterilizing water is manufactured by properly feeding and mixing three liquids of water, an acid solution, and a chlorine-based solution at a fully controlled concentration. In the apparatus for manufacturing sterilizing water of some aspect of the present invention, after both acid solution and chlorine-based solution have been diluted with raw water in a feeder, the dilute solutions can be mixed with each other by a mixer.

TECHNICAL FIELD

The present invention relates to an apparatus for manufacturingsterilizing water used for food processing, stock raising, medical care,and the like. More particularly, it relates to an apparatus formanufacturing sterilizing water that accomplishes chlorination by sodiumhypochlorite solution or chlorine dioxide solution.

BACKGROUND ART

Conventionally, sodium hypochlorite solution having sterilizingproperties has been used as a bleaching agent or a mold remover. Also,the use of chlorine dioxide for sterilization of city water has beenstudied. Such sterilizing water in which the concentration of chlorineis increased as compared with city water etc. to enhance thesterilization power has been used at job sites requiring sterilization,for example, for HACCP-compatible food processing, stock raising such asbreeding of SPF pigs, and medical care.

It is known that the bactericidal action of the above-describedchlorine-based compound changes greatly according to the state of thechlorine-based compound in aqueous solution, and depends heavily on theacidity (pH). Especially in the case of sodium hypochlorite,bactericidal action differs greatly depending on the pH range, between astrongly acidic condition, a weakly acidic through neutral condition,and an alkaline condition.

In the strongly acidic condition (where pH is lower than 3.8), chlorinegas is liberated from sodium hypochlorite solution. This chlorine gas istoxic, and hence the application of the manufactured sterilizing wateris undesirably limited to a substantial extent, though the sterilizingwater has a bactericidal action. Also, in the alkaline condition (wherepH exceeds 7.5), the ratio of ionization of chlorine in the solutioninto the form of hypochlorous acid ion (OCl—) increases. Thehypochlorous acid ion has weak sterilization power, being about 1/80 ofthe sterilization power of hypochlorous acid (HOCL) with the samechlorine concentration. Therefore, to raise the sterilization power, thechlorine concentration must inevitably be increased. However, even ifsterilization power is raised by increasing the concentration, thoughsterilization power rises, the concentration has to be increased stillfurther, since sodium hypochlorite solution itself is alkaline,.

On the other hand, in the weakly acidic through neutral condition (wherepH is in the range of 4.8 to 7.5), a large amount of chlorine takes theform of hypochlorous acid (HOCI), so that the sterilization power candesirably be raised without the production of chlorine gas. For example,Japanese Patent Provisional Publication No. 10-182325 (No. 182325/1998)has discloses a “Device for Reinforcing Sterilization Power of SodiumHypochlorite”. This Document discloses that either acid orchlorine-based solution is diluted and fed to a water flow by separatefeeders. In this disclosure, acid solution or chlorine-based solution ispoured into a flow path by a pump. A configuration is mainly disclosed,in which hypochlorous acid is fed to the water flow from achlorine-based solution tank by a pump, and subsequently acid is fed bya pump. Further, in mixing, mixing means consisting of an agitator orthe like is used.

However, the apparatus and method for manufacturing sterilizing waterdisclosed until now have the following problems:

(1) In the publicly known configuration, an acid is used to make theliquid into a weakly acidic condition, wherein the finally manufacturedsterilizing water, chlorine gas is liable to be produced due tononuniform concentration of acid or hypochlorous acid.

(2) In order to control the acidic water to which sodium hypochloritesolution is fed so as to provide a proper acidity, a precise controlsystem is needed, and also, a plurality of feeders are needed. Thus, theapparatus becomes large in scale, and the installation location islimited, resulting in a high cost.

(3) Also, a pump is used to feed acid or sodium hypochlorite, meaningthat the pump must be controlled with high accuracy.

Furthermore, while an agitator etc. could also be used in a mixer, sucha configuration has the following problems:

(4) A mixer which comprises an agitator or the like desirably has afixed shape in order to mix the liquid efficiently, but the materialthereof is limited because the mixer itself is used to mix solutions ina wide range of acidity conditions, from acidic condition to alkalinecondition. In particular, when a resin is used to make a mixer, nosuitable mixer is known in terms of acid resistance and alkaliresistance.

(5) Where the flow path must be straight in order to arrange the mixerin the flow path, the design of the whole of the apparatus is severelyrestricted, and making the equipment smaller is hindered.

Furthermore, a Venturi type feeding method, which utilizes negativepressure, could also be adopted for feeding acid or hypochlorous acidaccording to the quantity of production per unit time of the sterilizingwater. However, this method has the following problems:

(6) Where a pump for producing a water flow is arranged on the upstreamside of a mixer, acidic water is produced by a Venturi type feeder andfurther sodium hypochlorite solution is fed by the Venturi type feeder,and a faucet etc. are provided on the downstream side thereof as anoutlet for the sterilizing water. In such a case, since the degree ofopening of the faucet can be adjusted arbitrarily, acid solution andsodium hypochlorite solution must be fed in proportion to the currentflow rate according to the degree of opening of the faucet.

(7) With this method, it is necessary to precisely control a very lowflow rate of the feed chemical. If the flow rate is controlled by usinga needle type flow regulator, the shape of an opening for restrictingthe flow rate becomes a doughnut shape or the like having a very smallcross section, so that the flow rate is varied by the deformation offlow regulator due to thermal expansion of material of the flowregulator caused by a change in environmental temperature. Thisphenomenon is particularly prominent when the flow regulator is made ofa resin to ensure chemical resistance. Further, if small quantities ofdust etc. are contained in the flowing liquid, the flow path is soonclogged, which hinders stable feeding operation.

(8) The negative pressure for this suction feeding operation isapproximately 100 to 1000 mm in water-gauge pressure (=about 980 to 9800Pa=about 0.00968 to 0.0968 atm). This negative pressure is at the samelevel as the pressure produced by a difference in height of water ofabout 10 cm. Therefore, the flow rate of the suction fed liquid isaffected by a minute change in pressure of water flow that achievessuction.

(9) When the whole of the apparatus is in actual use, it is favorable toprovide a safety device that monitors the quantity of feeding of acid orhypochlorous acid as appropriate so that the supply of sterilizing wateris shut off when the flow rate exceeds a certain value. In this case,the manufacture path of sterilizing water can be shut off by using anelectromagnetic valve etc. as the safety device. However, if the flowrate in the supply path of acid or hypochlorous acid is used as thejudgment criterion, a flow sensor is needed to detect the flow rate inthe supply path of acid or hypochlorous acid. An inexpensive flow sensorthat has high chemical resistance and is capable of detecting a very lowflow rate sensitively is not yet known.

(10) Furthermore, if the path to be detected contains air bubbles, theflow sensor generally produces an error. When the apparatus formanufacturing sterilizing water is in actual use, it is favorable tomaintain a state in which air bubbles do not intrude into the pathduring the operation and shutdown of the apparatus.

(11) Also, when acidic solution or chlorine-based solution is fed at alow flow rate, even if it is attempted to directly regulate the quantityof feeding thereof, dust etc. contained in the solution exerts aninfluence on the regulating portion, so that it is not easy to performstable operation for a long period of time.

DISCLOSURE OF THE INVENTION

The present invention has been made to solve at least some of theabove-described problems. An object of the present invention is toprovide an apparatus for manufacturing sterilizing water, which fullyachieves the sterilization power of a chlorine-based solution whilerestraining the generation of chlorine gas, and has a simpleconstruction. Another object of the present invention is to provide anapparatus for manufacturing sterilizing water, which restrainsfluctuations of pressure affecting feeding, and thereby realizingstable. feeding. Still another object of the present invention is toprovide a mixer capable of accomplishing mixing properly at a low cost,a flow rate regulator capable of stably restricting the flow rate evenif the flow rate is very low, and an inexpensive flow sensor capable ofdetecting a very low flow rate properly.

In the present invention, there is provided an apparatus formanufacturing sterilizing water, which can manufacture desiredsterilizing water by properly feeding and mixing three liquids of water,an acid solution, and a chlorine-based solution at a fully controlledconcentration. The water is used in larger quantities than the acidsolution and chlorine-based solution. In the apparatus for manufacturingsterilizing water in accordance with the present invention, after bothof the acid solution and the chlorine-based solution have been dilutedwith raw water in a feeder, the dilute solutions can be mixed with eachother.

Therefore, the present invention provides an apparatus for manufacturingsterilizing water, in which sterilizing water is manufactured by mixingan acid solution consisting of hydrochloric acid or acetic acid or amixture thereof and a chlorine-based solution consisting of sodiumhypochlorite or chlorine dioxide or a mixture thereof with water,including a feeder provided with a first flow path, in which the acidsolution is fed to a part of a water flow to produce a dilute acidsolution, and a second flow path, in which the chlorine-based solutionis fed to the remainder of the water flow to produce a dilutechlorine-based solution; and a mixer which is arranged on the downstreamside of the first and second flow paths to mix the dilute acid solutionsent from the first flow path with the dilute chlorine-based solutionsent from the 'second flow path.

By this configuration, the acid solution and chlorine-based solution canbe fed and mixed while being diluted without the use of a plurality offeeders, so that an apparatus for manufacturing sterilizing water havinga simple construction can be manufactured.

In this configuration, the configuration can be made such that thefeeder is a feeder for feeding the acid solution and the chlorine-basedsolution by suction utilizing a negative pressure produced in waterflows in the first and second flow paths, so that feeding using a pumpis not performed.

A line pump is not needed in the feeding lines for the acid solution andthe chlorine-based solution, so that the apparatus for manufacturingsterilizing water can be manufactured easily.

Further, in the above-described apparatus for manufacturing sterilizingwater, the configuration can be made such that the first and second flowpaths are separated by a separation wall.

The separation wall has a function of preventing the acid solution andchlorine-based solution from being brought into contact with each otherwithout being diluted fully. The construction, arrangement, material,and forming method of separation wall are arbitrary, but the separationwall is arranged in such a manner that the liquids flowing in the firstand second flow paths are not mixed. As the separation wall, forexample, a plate member can be used. In this case, since the separationwall can be placed after the drum portion of the mixer has been machinedinto a shape symmetrical about its axis so that machining accuracy canbe ensured easily, a mixer which is highly accurate even if it is smallin size can be manufactured, and thus an apparatus for manufacturingsterilizing water capable of obtaining sterilizing water having a stableconcentration is provided.

In the apparatus for manufacturing sterilizing water of another aspectof the present invention as well, similarly, three liquids of water,acid solution, and chlorine-based solution are fed and mixed in thefeeder. Herein, the chlorine-based solution can be fed to the acidsolution having been diluted with water. At this time, the acid solutionand chlorine-based solution are mixed after at least the acid solutionhas been diluted.

Thus, the present invention provides an apparatus for manufacturingsterilizing water, in which sterilizing water is manufactured by mixingan acid solution consisting of hydrochloric acid or acetic acid or amixture thereof and a chlorine-based solution consisting of sodiumhypochlorite or chlorine dioxide or a mixture thereof with water,including a feeder, which is provided with a flow path for feeding theacid solution to a water flow to produce a dilute acid solution, forfeeding the chlorine-based solution to the dilute acid solution; and amixer which is arranged on the downstream side of the feeder to mix thewater flow.

By this configuration, the dilute acid solution is prepared and then thechlorine-based solution is fed by a single feeder. In thisconfiguration, even if one feeder is used, sterilizing water havingsufficient sterilization power, for example, sterilizing waterexhibiting a liquid property from weakly acid to neutral and having ahypochlorous acid concentration of about 200 ppm can be obtained.Moreover, chlorine gas is scarcely generated.

In the configuration, further, the feeder is a feeder for feeding theacid solution and the chlorine-based solution by suction utilizing anegative pressure produced in the water flow, so that the configurationcan be made such that feeding using a pump is not performed.

Since a pump need not be provided in the feeding line to performfeeding, an apparatus for manufacturing sterilizing water having asimple construction can be manufactured.

In all aspects of the present invention mentioned above, theconfiguration can be made such that the feeder is provided with amovable portion that performs opening/closing operation of flow path forthe water flow by the water supply pressure of water flow, and by theopening/closing operation, a check valve for feeding at least either ofthe acid solution and the chlorine-based solution is opened or closed.

If the configuration is made as described above, when the supplied waterflow has a pressure not higher than a predetermined pressure, the flowshuts off, so that the acid solution and chlorine-based solution can beprevented from flowing out to the flow path. Thereby, when waterscarcely flows, the acid solution and chlorine-based solution can beprevented from flowing out. Therefore, the mixing of the acid solutionand the chlorine-based solution at an unintendedly high concentrationcan be prevented.

If this movable portion performs opening/closing operation with a fixedpressure being a threshold value by using a spring, in the apparatus formanufacturing sterilizing water in accordance with the presentinvention, the mixing of the acid solution and chlorine-based solutioncan be controlled by water supply pressure.

Also, in the above-described aspect of the present invention, theconfiguration may be such that the check valve provided in the path forthe chlorine-based solution has this movable portion. Thereby, anapparatus for manufacturing sterilizing water, which operates well evenif the number of parts is small, is provided.

In any aspect of the above-described invention, the mixer can be made astatic mixer in which the water flow is mixed so that the water flow ismade a substantially turbulent flow.

The expression, “the water flow is made a substantially turbulent flow”means that the water flow does not consist of a substantially laminarflow or steady vortexes only, but the water flow can be regarded as aturbulent flow by producing vortexes (Karman vortex street) changingwith time. The water flow includes the flow of not only water but alsoliquids obtained by diluting the acid solution and chlorine-basedsolution.

In the above-described aspect of the present invention, theconfiguration can be made such that the mixer is a mixer in which mixingis performed in the water flow in a tube, and is a static mixer in whicha plurality of mixing blades having different directions are arranged inthe tube along the lengthwise direction of the tube, and a substantiallyturbulent flow is produced in the water flow in the tube by each of themixing blades, by which the water flow is mixed.

In this case, mixing blades having different directions are manufacturedso that vortexes or a turbulent flow (substantially turbulent flow) thatrepeatedly appears and disappears over time, such as Karman vortexstreet, with respect to the water flow can be generated on thedownstream side of each blade. Due to the mixing blades, mixing can beperformed efficiently without the production of great resistance in theflow. The mixing blade has only to generate a substantially turbulentflow. The shape of mixing blade is not subject to any specialrestriction if the mixing blade has a construction that generates asubstantially turbulent flow. The mixing blades are arranged so as to bedirected in different directions. Thereby, all parts of the waterflowing in the mixer are mixed by the substantially turbulent flow, andthe water flow passing through the mixing blades is fully mixed.Therefore, in the manufactured sterilizing water, variations inconcentration of acid and chlorine are less liable to occur. Thus, theapparatus for manufacturing sterilizing water in accordance with thepresent invention can manufacture homogeneous sterilizing water capableof restraining the generation of chlorine gas.

Also, the mixing blade can have a fixed thickness. By making thethickness not smaller than a fixed value, a substantially turbulent flowsuch as a proper Karman vortex is induced, so that mixing can beperformed satisfactorily.

In addition, the mixing blades can be manufactured by twisting a planeshaped plate member in connecting portions with narrow widths, which areprovided on the plate member.

As an example of such mixing blades, a member which has narrow widths atintervals is prepared by using a plate member (for example, a platemember having the same width as the inside diameter of tube and havingalmost the same length as the length of tube forming the mixer), andportions having wider widths can be made mixing blades, and portionshaving narrower widths can be made connecting portions (refer to FIG.5(A)). By twisting the connecting portions through a fixed angle, mixingblades in which the individual mixing blades have different directionsin the tube can be manufactured easily (refer to FIG. 5(B)). Since themixing blades have outside diameters approximately equal to the insidediameter of tube, mixing blades having high mixing ability can bemanufactured easily merely by inserting the mixing blades into the tubeand by fixing the end portions thereof without the use of a specialsupport member.

The mixing blades are not necessarily limited to those shown in FIG.5(B). The twisting angle need not necessarily be regular. Also, it is amatter of course that the apparatus for manufacturing sterilizing waterin accordance with the present invention operates properly even if themixing blades of the present invention are manufactured by othermethods, for example, resin molding or three-dimensional machining.

In the present invention, means for producing the water flow is notregarded as important. An arbitrary conveying pump or suction pump canbe used. Also, a water source for supplying pre-pressurized water, suchas city water, may be used.

However, in all aspects of the above-described inventions, the waterflow can preferably be produced by a pump located on the upstream sideof the feeder. This configuration has an advantage that since the waterflow can be controlled by the discharge pressure of pump, the water flowis easily stabilized. Also, since the chemical, such as acid solutionand chlorine-based solution, does not come into contact with the pump,the pump need not be subjected to corrosion prevention. In the presentinvention, the type of pump is arbitrary, and, for example, aregenerative pump or the like can be used.

In all aspects of the above-described inventions, the chlorine-basedsolution can be made sodium hypochlorite, and the pH of the sterilizingwater can be made in the range of 4.8 to 7.5.

If the acidity (pH) is set in the above-described range in the case ofhypochlorous acid, proper sterilizing water can be realized. Also, inall apparatuses for manufacturing sterilizing water in accordance withthe present invention, the above-described sterilizing water can bemanufactured stably.

Also, in a method for manufacturing sterilizing water by mixing an acidsolution consisting of hydrochloric acid or acetic acid or a mixturethereof and a chlorine-based solution consisting of sodium hypochloriteor chlorine dioxide or a mixture thereof with water, a method formanufacturing sterilizing water is also effective which includes a flowdividing step of separating a water flow into a first flow path and asecond flow path; an acid diluting step of preparing a dilute acidsolution by feeding the acid solution to the first flow path, which stepfollows the flow dividing step; a chlorine-base solution diluting stepof preparing a dilute chlorine-based solution by feeding thechlorine-based solution to the second flow path; and a step of mixingthe dilute acid solution with the dilute chlorine-based solution, whichstep follows the acid diluting step and the chlorine-base solutiondiluting step.

Also, in a method for manufacturing sterilizing water by mixing an acidsolution consisting of hydrochloric acid or acetic acid or a mixturethereof and a chlorine-based solution consisting of sodium hypochloriteor chlorine dioxide or a mixture thereof with water, a method formanufacturing sterilizing water is also effective which includes an aciddiluting step of preparing a dilute acid solution by feeding the acidsolution to a water flow; a chlorine-based solution feeding step offeeding the chlorine-based solution, which step follows the aciddiluting step; and a step of mixing the water flow, which step followsthe chlorine-based solution feeding step.

In these manufacturing methods, the concentration of chlorine-basedsolution can be made in the range of 10 ppm to 400 ppm, preferably inthe range of 100 ppm to 300 ppm. If the sterilizing water having theconcentration of this range is manufactured by the above-describedmethod, the sterilization power is high, and the construction ofapparatus is simple, so that the practicability is high.

In the apparatus for manufacturing sterilizing water of another aspectof the present invention, both acid and chlorine-based solution can bemixed after being diluted with water in the feeders. At this time, thefeeder is not located at a position at which the flow rate is changed bythe influence of a faucet etc., and the diluted solution is once storedin a tank. This tank has a function of releasing the pressure.

That is to say, one aspect of the present invention provides anapparatus for manufacturing sterilizing water, in which sterilizingwater is manufactured by feeding an acid solution consisting ofhydrochloric acid or acetic acid or a mixture thereof and achlorine-based solution consisting of sodium hypochlorite or chlorinedioxide or a mixture thereof to water, including an acid solution feederfor feeding the acid solution to a part of a water flow to produce adilute acid solution; a dilute acid solution tank which stores thedilute acid solution and releases the supply pressure of part of thewater flow; a chlorine-based solution feeder for feeding thechlorine-based solution to a remainder of the water flow to produce adilute chlorine-based solution; a dilute chlorine-based solution tankwhich stores the dilute chlorine-based solution and releases the supplypressure of the remainder of the water flow; a suction water path whichhas two suction ports, and also has a joining portion for joining thedilute acid solution and the dilute chlorine-based solution together bysucking the dilute acid solution in the dilute acid solution tank andthe dilute chlorine-based solution in the dilute chlorine-based solutiontank from the two suction ports; a pump which is connected to thesuction water path to suck and discharge the dilute acid solution andthe dilute chlorine-based solution, which have been joined together, viathe suction water path; an acid solution mixer which is provided at anyposition between the acid solution feeder and the pump to mix the diluteacid solution; and a chlorine-based solution mixer which is provided atany position between the chlorine-based solution feeder and the pump tomix the dilute chlorine-based solution.

By this configuration, at a position on the upstream side of the tank inwhich the pressure is released, a flow rate suitable for the feeding ofacid solution and chlorine-based solution can be secured withoutdepending on the quantity of sterilizing water consumed. For example,for city water, the water pressure fluctuates, and hence a change canoccur in the water flow. However, the opening/closing operation offaucet for taking out sterilizing water to be used changes the waterflow in a far greater range. Therefore, it is effective to inhibit thefeeding of acid solution and chlorine-based solution at a position wherethe water flow can change depending on the usage of sterilizing waterand to eliminate an influence of the change in water flow due to theusage of sterilizing water by using a tank at an intermediate position.The tank not only prevents the supply pressure from the upstream sidefrom being transmitted to the downstream side but also prevents theusage of sterilizing water on the downstream side from affecting thewater flow on the upstream side.

In this aspect, an apparatus for manufacturing sterilizing water, inwhich the apparatus further includes a raw water tank and at least oneraw water pump for sucking raw water from the raw water tank to producethe water flow, wherein a part of the water flow and the remainder ofthe water flow are formed by the raw water pump, is also suitable. Theraw water tank is a tank for storing city water or water from otherwater sources. The raw water pump may be of any type that makes thewater in the raw water tank a water flow. Although the term “raw waterpump” is used for convenience, in addition to a pump that sucks rawwater, a pump which sucks raw water before the feeding of acidic waterby sucking, for example, a dilute acidic water to which acidic water hasbeen fed, also functions as a raw water pump. By the use of the rawwater tank, even if the pressure fluctuates, for example, as in the casewhere the raw water is city water, fluctuations in pressure can beprevented from affecting the water flow pressure and flow velocity atthe time when the acid solution and chlorine-based solution are fed.

Also, in this aspect, the raw water pump preferably includes a first rawwater pump for forming the part of the water flow to which the acidsolution is fed and a second raw water pump for forming the remainder ofthe water flow to which the chlorine-based solution is fed. If the firstraw water pump and the second raw water pump are used, the part of thewater flow to which the acid solution is fed and the remainder of thewater flow to which the chlorine-based solution is fed can be controlledindependently. Therefore, the dilution is accomplished stably, and hencethe sterilizing water can be manufactured stably.

Further, in this aspect, the apparatus for manufacturing sterilizingwater can be configured so that the suction water path has water pathsleading from each of the two suction ports to the joining portion; theacid solution mixer is provided in the water path between the suctionport, through which the dilute acid solution is sucked from the diluteacid solution tank, and the joining portion; the chlorine-based solutionmixer is provided in the water path between the suction port, throughwhich the dilute chlorine-based solution is sucked from the dilutechlorine-based solution tank, and the joining portion; and a joiningmixer is further provided between the joining portion and the pump. Ifthe mixers are arranged in this manner, sterilizing water in whichmixing is performed sufficiently and homogeneous mixing is realized canbe produced.

Further, the apparatus for manufacturing sterilizing water can beconfigured so that the acid solution mixer is provided between the acidsolution feeder and the dilute acid solution tank, and thechlorine-based solution mixer is provided between the chlorine-basedsolution feeder and the dilute chlorine-based solution tank. Even in thecase where the mixers are arranged in this manner, sterilizing water inwhich mixing is performed sufficiently and homogeneous mixing isrealized can be produced.

In another aspect of the present invention, there is provided anapparatus for manufacturing sterilizing water, in which sterilizingwater is manufactured by feeding an acid solution consisting ofhydrochloric acid or acetic acid or a mixture thereof and achlorine-based solution consisting of sodium hypochlorite or chlorinedioxide or a mixture thereof to water, including an acid solution feederfor feeding the acid solution to a water flow to produce a dilute acidsolution; a dilute acid solution tank which stores the dilute acidsolution and releases the supply pressure of a part of the water flow; apump for sucking the dilute acid solution from the dilute acid solutiontank; a chlorine-based solution feeder for feeding the chlorine-basedsolution to the water flow from the dilute acid solution tank, which isproduced by the pump; an acid solution mixer which is provided at anyposition in a water path leading from the acid solution feeder to thechlorine-based solution feeder to mix the dilute acid solution; and achlorine-based solution mixer which is provided at any position in awater path leading from the chlorine-based solution feeder to the pumpto mix the chlorine-based solution. By storing the dilute acid solutiononce by using the tank in this manner, the feeding rate of acid solutionthat influences the pH is determined without being affected by the usageof sterilizing water.

In this aspect, it is also suitable that the apparatus for manufacturingsterilizing water further includes a raw water tank; a raw water pumpfor sucking raw water from the raw water tank to produce the water flow;and a sterilizing water tank for storing the manufactured sterilizingwater, wherein a part of the water flow and the remainder of the waterflow are formed by the raw water pump. By using the raw water tank andthe raw water pump, even when the raw water is city water etc.,sterilizing water can be manufactured stably without being affected bythe fluctuations in pressure of the raw water.

In this configuration, the acid solution mixer can be provided betweenthe dilute acid solution tank and the chlorine-based solution feeder. Ifthe mixer is arranged in this manner, sterilizing water can be producedin which mixing is performed sufficiently and homogeneous mixing isrealized.

Also, the acid solution mixer can be provided between the acid solutionfeeder and the dilute acid solution tank. If the mixer is arranged inthis manner as well, sterilizing water can be produced in which mixingis performed sufficiently and homogeneous mixing is realized.

In another aspect of the present invention, there is provided anapparatus for manufacturing sterilizing water, in which sterilizingwater is manufactured by feeding an acid solution consisting ofhydrochloric acid or acetic acid or a mixture thereof and achlorine-based solution consisting of sodium hypochlorite or chlorinedioxide or a mixture thereof to water, including an acid solution feederfor feeding the acid solution to a part of a water flow to produce adilute acid solution; an acid solution mixer provided on the downstreamside of the acid solution feeder; a chlorine-based solution feeder forfeeding the chlorine-based solution to the remainder of the water flowto produce a dilute chlorine-based solution; a chlorine-based solutionmixer provided on the downstream side of the chlorine-based solutionfeeder; a joining portion for joining the dilute acid solution sent fromthe acid solution mixer and the dilute chlorine-based solution sent fromthe chlorine-based solution mixer together; a joining mixer for mixingthe dilute acid solution with the dilute chlorine-based solution at aposition on the downstream side of the joining portion; a pump forsucking and discharging a solution mixed on the downstream side of thejoining mixer; and a tank for storing sterilizing water discharged bythe pump. When the tank for storing the sterilizing water is used,sterilizing water can be manufactured regardless of the usage ofsterilizing water, so that the water flow need not be changed greatlydepending on the usage of sterilizing water.

As another aspect of the present invention, there is provided anapparatus for manufacturing sterilizing water, in which sterilizingwater is manufactured by feeding an acid solution consisting ofhydrochloric acid or acetic acid or a mixture thereof and achlorine-based solution consisting of sodium hypochlorite or chlorinedioxide or a mixture thereof to water, including a raw water tank; a rawwater pump for sucking raw water from the raw water tank to produce awater flow; an acid solution feeder for feeding the acid solution to thewater flow to produce a dilute acid solution; a chlorine-based solutionfeeder for further feeding the chlorine-based solution to the waterflow; an acid solution mixer which is provided at any position in awater path leading from the acid solution feeder to the chlorine-basedsolution feeder to mix the dilute acid solution; a chlorine-basedsolution mixer which is provided at any position on the downstream sideof the chlorine-based solution feeder to mix the chlorine-basedsolution; and a sterilizing water tank which is provided on thedownstream side of the chlorine-based solution mixer to store themanufactured sterilizing water. By this configuration, by using the rawwater tank and the raw water pump, even when the raw water is city wateretc., sterilizing water can be manufactured stably without beingaffected by the fluctuations in pressure of the raw water.

In another aspect of the present invention, an apparatus formanufacturing sterilizing water, in which sterilizing water ismanufactured by feeding an acid solution consisting of hydrochloric acidor acetic acid or a mixture thereof and a chlorine-based solutionconsisting of sodium hypochlorite or chlorine dioxide or a mixturethereof to water, including a pump for discharging raw water to producea water flow; an acid solution feeder for feeding the acid solution to apart of a water flow to produce a dilute acid solution; an acid solutionmixer provided on the downstream side of the acid solution feeder; achlorine-based solution feeder for feeding the chlorine-based solutionto the remainder of the water flow to produce a dilute chlorine-basedsolution; a chlorine-based solution mixer provided on the downstreamside of the chlorine-based solution feeder; a joining portion forjoining the dilute acid solution sent from the acid solution mixer andthe dilute chlorine-based solution sent from the chlorine-based solutionmixer together; a joining mixer for mixing the dilute acid solution withthe dilute chlorine-based solution at a position on the downstream sideof the joining portion; and a tank for storing sterilizing watermanufactured by joining. In this case as well, when the tank for storingthe sterilizing water is used, sterilizing water can be manufacturedregardless of the usage of sterilizing water, so that the water flowneed not be changed greatly depending on the usage of sterilizing water.

In each aspect of the above-described invention, the configuration canbe made such that at least either of the acid solution feeder or thechlorine-based solution feeder is a feeder for feeding the acid solutionor the chlorine-based solution by suction utilizing a negative pressureproduced in the water flow, so that feeding using a pump is notperformed. Since there is no relation between the usage of sterilizingwater and the water flow because the tank is used, stable feeding isrealized by using the feeder for suction feeding without performingmixing using a pump.

Also, in each aspect of the above-described invention, at least any oneof the acid solution mixer, the chlorine-based solution mixer, and thejoining mixer can be made a static mixer for the water flow so as toproduce a substantially turbulent flow. The static mixer also operatesstably since there is no relation between the usage of sterilizing waterand the water flow because the tank is used. The substantially turbulentflow includes Karman vortex, a standing vortex that is considered tofully become a turbulent flow, and the like. It has only to sufficientlyperform a function of mixing or agitation. Since such a turbulent flowrelates closely to the velocity of water flow in the static mixer, thestatic mixer can be operated properly especially when there is norelation between the usage of sterilizing water and the water flow as inthe present invention.

In the present invention, there is provided a static mixer including atube serving as a water path; and many mixing elements provided in thetube so as to be arranged in the direction of a flow in the tube,characterized in that the mixing element has a joint for keeping anangular difference around the axis of the tube with respect to theadjacent mixing element; and the joint has a shape of polygon in crosssection so as to provide a flexible construction such that many mixingelements are arranged along the bend of tube, and when the arrangementdirection of mixing elements is bent, the mixing elements can follow thebent while the angular difference is kept. When the static mixer is madeof a highly chemical resistant resin etc., if it is intended toaccommodate the bend of tube by using the above-described joint, themixer can be realized in a bent pipe. Also, the mixer can also bemanufactured by using a flexible pipe.

This static mixer can be used for an apparatus for manufacturingsterilizing water using a static mixer in which the water flow is made asubstantially turbulent flow and is mixed. Even such a static mixer canproduce a substantially turbulent flow.

In the present invention, there is provided a regulator including aturret portion which has a plurality of flow rate restricting orificeshaving different inside diameters, and is capable of being turned toselect any of the flow rate restricting orifices; and a turret receivingportion which rotatably holds the turret portion, and has a flow pathaligning with any of the flow rate restricting orifices. The flow raterestricting orifice can be made a circular opening. The orifice is lessliable to be clogged as compared with a slit achieving the same flowrate restricting effect, and less liable to exert an adverse influencesuch that strain etc. of material due to a temperature change cause achange in flow rate.

The apparatus for manufacturing sterilizing water may be configured sothat this regulator is inserted in at least either of the flow paths forthe acid solution and the chlorine-based solution fed by either feeder.The above-described regulator is suitable for regulating the feeding ofthe acid solution and chlorine-based solution of a very low flow rate asin the sterilizing water described in the aspects of the presentinvention.

In the present invention, there is provided a flow sensor including acylindrical piston member which is made of a material having lighttransmitting properties, and moves in the axial direction; a cylinderportion which movably holds the piston member with the axial directionof the piston member being directed in the substantially verticaldirection, has a cylindrical inside side surface, and is provided with aplurality of minute holes arranged in the inside side surface so thatthe minute holes serve as a flow path in succession according to theaxial displacement of the piston member; a front chamber and a rearchamber which are separated from each other by the cylinder portion andthe piston member, and are connected to each other by the minute holes;a light intercepting member which moves together with the piston member;a light emitting element which emits either light of ultraviolet rays,visible rays, and infrared rays, and is arranged so that a light path isformed in the range in which the light intercepting member moves withthe light being used as detection light; and a light receiving elementwhich is arranged to receive the light of the light emitting element sothat it can be detected that the light intercepting member is located inthe light path, characterized in that the flow sensor is used in anorientation such that when the piston member moves downward due togravity, the minute holes are closed; when a differential pressureobtained by removing the pressure of working fluid in the rear chamberfrom the pressure of working fluid in the front chamber is not higherthan a predetermined working pressure, a movable member consisting ofthe light intercepting member and the piston member closes at least someof the minute holes, and when the differential pressure becomes higherthan the predetermined working pressure, the movable member moves upwardaccording to the differential pressure, and operates so as to open theclosed minute holes in succession to cause a large quantity of workingfluid to flow from the front chamber to the rear chamber; and a changein the detected light quantity produced by the interception of the lightpath caused by the light intercepting portion of the movable membermoved by a change in the differential pressure is detected by the lightreceiving element, and the flow rate of the working fluid is detectedbased on a change in the output signal. Such a flow sensor can bemanufactured at a low cost. In particular, if a portion that is incontact with the liquid is made of a resin, the flow sensor can operatestably. Also, the flow sensor can detect the flow sensitively even ifthe flow rate is very low.

In the apparatus for manufacturing sterilizing water in accordance withthe present invention, an electromagnetic valve capable of shutting offthe outflow of sterilizing water is further provided in at least eitherwater path; and the electromagnetic valve can be controlled according tothe output signal by using this flow sensor in the flow path for thechemical fed by either feeder. By using an inexpensive and sensitiveflow sensor having high chemical resistance, the apparatus formanufacturing sterilizing water in accordance with the present inventioncan gain high practicability at a low cost.

In all aspects of the present invention, the type of pump is arbitrary,and, for example, a regenerative pump or the like can be used.

Also, the chlorine-based solution can be made sodium hypochlorite, andthe pH of the sterilizing water can be made in the range of 4.8 to 7.5.If the acidity (pH) is set in the above-described range in the case ofhypochlorous acid, proper sterilizing water can be realized. Also, inall apparatuses for manufacturing sterilizing water in accordance withthe present invention, the above-described sterilizing water can bemanufactured stably.

Also, in a method for manufacturing sterilizing water by mixing an acidsolution consisting of hydrochloric acid or acetic acid or a mixturethereof and a chlorine-based solution consisting of sodium hypochloriteor chlorine dioxide or a mixture thereof with water, a method formanufacturing sterilizing water is also effective which includes a flowdividing step of separating a water flow into a first flow path and asecond flow path; an acid diluting step of preparing a dilute acidsolution by feeding the acid to the first flow path, which step followsthe flow dividing step; a chlorine-base solution diluting step ofpreparing a dilute chlorine-based solution by feeding the chlorine-basedsolution to the second flow path; and a step of mixing the dilute acidsolution with the dilute chlorine-based solution, which step follows theacid diluting step and the chlorine-base solution diluting step.

Also, in a method for manufacturing sterilizing water by mixing an acidsolution consisting of hydrochloric acid or acetic acid or a mixturethereof and a chlorine-based solution consisting of sodium hypochloriteor chlorine dioxide or a mixture thereof with water, a method formanufacturing sterilizing water is also effective which includes an aciddiluting step of preparing a dilute acid solution by feeding the acid toa water flow; a chlorine-based solution feeding step of feeding thechlorine-based solution, which step follows the acid diluting step; anda step of mixing the water flow, which step follows the chlorine-basedsolution feeding step.

In these manufacturing methods, the concentration of chlorine-basedsolution can be made in the range of 10 ppm to 400 ppm, preferably inthe range of 100 ppm to 300 ppm. If sterilizing water having aconcentration in this range is manufactured by the above-describedmethod, its sterilization power is high, and the construction of itsapparatus is simple, so that the practicability is high.

In the present invention, there is provided an apparatus formanufacturing sterilizing water, in which sterilizing water ismanufactured by feeding an acid solution consisting of hydrochloric acidor acetic acid or a mixture thereof and a chlorine-based solutionconsisting of sodium hypochlorite or chlorine dioxide or a mixturethereof to water, including a first water path; a first feeder, which isprovided in the first water path, for feeding the acid solution; asecond water path, which is divided from the first water path at aposition on the upstream side of the first feeder and is returned to thefirst water path at a position on the downstream side of the firstfeeder; a second feeder, which is provided in the second water path, forfeeding the chlorine-based solution; a first bypass water path which isdivided from the first water path and is returned to the first waterpath to bypass the first feeder; a second bypass water path which isdivided from the second water path and is returned to the second waterpath to bypass the second feeder; a first flow rate restricting valveprovided in the first bypass water path; a second flow rate restrictingvalve provided in the second bypass water path; and a sterilizing watertank for receiving a water flow in the first water path.

Also, in the present invention, there is provided an apparatus formanufacturing sterilizing water, in which sterilizing water ismanufactured by feeding an acid solution consisting of hydrochloric acidor acetic acid or a mixture thereof and a chlorine-based solutionconsisting of sodium hypochlorite or chlorine dioxide or a mixturethereof to water, including a main water path; a first feeder, which isprovided in the main water path, for feeding the acid solution to awater flow; a second feeder, which is provided in the main water flow soas to be located on the downstream side of the first feeder, for feedingthe chlorine-based solution; a first bypass water path which is dividedfrom the main water path and is returned to the main water path tobypass the first feeder; a second bypass water path which is dividedfrom the main water path and is returned to the main water path tobypass the second feeder; a first flow rate restricting valve providedin the first bypass water path; a second flow rate restricting valveprovided in the second bypass water path; and a sterilizing water tankfor receiving a water flow in the main water path.

If the bypass water path arranged in parallel with the feeder is used,and the flow rate restricting valve is further provided in the bypasswater path, the flow rate in the bypass water path can be adjusted byfully opening, partially opening, or fully closing the valve. Inparticular, if the bypass water path is provided for each feeder, thefeeding using the feeder can be controlled by adjusting the flow raterestricting valve in the bypass water path, so that satisfactory feedingis realized. In the above-described apparatus for manufacturingsterilizing water, by the above-described configuration, the feeder isoperated under a condition suitable for feeding, and the concentrationof acid solution and chlorine-based solution in the water flow can bedecreased by using the bypass water path. Therefore, the operations offeeding and dilution can be set so as to meet the respective objectives,so that the stable operation can be performed. Also, by adjusting theflow rate in the bypass water path at the time when the apparatus formanufacturing sterilizing water is installed, the manufacturingconditions for the sterilizing water can be kept proper even if the rawwater for producing the sterilizing water has various water quality,supply quantities, or pressures.

The sterilizing water tank can be configured so that a vessel having acertain overflow level is provided; at least any of the water pathsleading to the sterilizing water tank has an outflow port arranged belowthe overflow level in the vessel; and the sterilizing water tank storesthe liquid overflowing the vessel.

When the sterilizing water tank is used, it is effective to use a vesselwhich stores liquid therein to a certain volume and overflows if theliquid is further added (for example, a vessel whose upper side is open,a vessel provided with an outflow port in the side surface thereof). Ifthe water path for causing the liquid to flow to the sterilizing watertank has an outflow port disposed at an inside position lower than theoverflow level of the vessel, the water pressure applied to the outflowport of the water path is fixed regardless of the quantity ofsterilizing water stored in the sterilizing water tank. Moreover, no airintrudes from the outflow port of water path even when the apparatus isshut down. Therefore, the pressure on the downstream side of the suctiontype feeder provided in the water path is stabilized, and hence thefeeding operation of the suction type feeder is stabilized.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a system diagram showing a configuration of an apparatus formanufacturing sterilizing water in accordance with one embodiment of thepresent invention;

FIG. 2 is a partially cutaway perspective view showing schematicconstructions of a feeder and a mixer in accordance with an example ofthe present invention;

FIG. 3 is a sectional view showing constructions of a feeder and a mixerin accordance with an example of the present invention;

FIG. 4 is a sectional view showing a construction of a chemicalintroduction assembly in accordance with an example of the presentinvention;

FIG. 5 is a schematic view showing a configuration and operation ofmixing blades of a mixer in accordance with an example of the presentinvention;

FIG. 6 is a system diagram showing a configuration of an apparatus formanufacturing sterilizing water in accordance with another embodiment ofthe present invention;

FIG. 7 is a sectional view showing constructions of a feeder and a mixerin accordance with an example of the present invention;

FIG. 8 is a system diagram showing a configuration of an apparatus formanufacturing sterilizing water in accordance with still anotherembodiment of the present invention;

FIG. 9 is a system diagram showing a configuration of an apparatus formanufacturing sterilizing water in accordance with still anotherembodiment of the present invention;

FIG. 10 is a system diagram showing a configuration of an apparatus formanufacturing sterilizing water in accordance with still anotherembodiment of the present invention;

FIG. 11 is a partially sectional plan view showing a construction of anassembly in accordance with an example of the present invention;

FIG. 12 is a partially sectional side view showing a construction of anassembly in accordance with an example of the present invention;

FIG. 13 is a view showing a construction of a mixing element used in anexample of the present invention;

FIG. 14 is a sectional view showing a construction of a principal partof a regulator used in an example of the present invention;

FIG. 15 is a sectional view showing a construction of a flow sensor usedin an example of the present invention;

FIG. 16 is a system diagram showing a configuration of an apparatus formanufacturing sterilizing water in accordance with still anotherembodiment of the present invention;

FIG. 17 is a system diagram showing a configuration of an apparatus formanufacturing sterilizing water in accordance with still anotherembodiment of the present invention;

FIG. 18 is a system diagram showing a configuration of an apparatus formanufacturing sterilizing water in accordance with still anotherembodiment of the present invention;

FIG. 19 is a system diagram showing a configuration of an apparatus formanufacturing sterilizing water in accordance with still anotherembodiment of the present invention; and

FIG. 20 is a system diagram showing a configuration of an apparatus formanufacturing sterilizing water in accordance with still anotherembodiment of the present invention.

BEST MODE FOR CARRYING OUT THE INVENTION

Embodiments of the present invention will now be described in detail.

[First Embodiment]

An embodiment of the present invention will be described. FIG. 1 is aschematic system view of an apparatus 100 for manufacturing sterilizingwater in accordance with one embodiment of the present invention.

In the apparatus 100 for manufacturing sterilizing water, raw water I issucked and supplied under pressure by a suitable pump 11, and to thesupplied raw water 1, an acid solution 21 is fed from an acid tank 2 toform an acidic water, and further a chlorine-based solution 31 is fedfrom a chlorine-based solution tank 3, by which sterilizing water ismanufactured. The configuration is such that the quantity of feeding ofthe acid solution 21 is controlled by a flow rate regulating portion 22,and when the water flow is shut off by a check valve 23, a flow path 6is isolated from the acid tank 2.

The raw water 1 is not subject to any special restriction, and purewater, city water, river water, underground water, and the like aresuitably used according to the application. As the acid solution 21,hydrochloric acid (hydrogen chloride solution) with a suitableconcentration (for example, 8.5%), acetic acid, and the like are used.Also, as the chlorine-based solution 31, sodium hypochlorite solutionwith a suitable concentration (for example, 12%), chlorine dioxide, andthe like are used.

The raw water I is divided by a first flow path 6 and a second flow path7, and the acid solution 21 and the chlorine-based solution 31 are fedto each of the divided raw water 1. The acid solution 21 is fed to theraw water in a feeding portion 41 and diluted to yield a dilute acidsolution. Also, the chlorine-based solution 31 is fed to the raw waterin a feeding portion 42 and diluted to yield a dilute chlorine-basedsolution. The dilute acid solution and the dilute chlorine-basedsolution are mixed with each other in a mixer 5 provided on thedownstream side of the feeding portions 41 and 42, by which sterilizingwater 81 containing water, acid solution, and chlorine-based solution ismanufactured. The sterilizing water 81 may be stored in a tank 8.Alternatively, the sterilizing water 81 may be used directly assterilizing water. When the sterilizing water 81 is stored in the tank8, the quantity of sterilizing water in the tank is detected by a liquidlevel sensor 9, and the pump 11 is controlled by control means 10 sothat a fixed quantity of sterilizing water can be maintained.

In this embodiment, both of the feeding portion 41 and the feedingportion 42 are provided in a feeder 4. The feeder 4 includes both of thefirst flow path 7 for feeding the acid solution to the raw water I andthe second flow path 6.

(General Explanation of Example)

Next, examples of the feeder 4 and the mixer 5 that realize theembodiment used for the apparatus for manufacturing sterilizing watershown in the system diagram as shown in FIG. 1 will be explained withreference to FIGS. 2 and 3. FIG. 2 is a partially cutaway perspectiveview showing schematic constructions of the feeder 40 and the mixer 50of this example. In this example, the feeder 40 and the mixer 50 bothhave a cylindrical appearance, and are connected to each other by aconnecting portion 59. Also, FIG. 3 is a sectional view showingconstructions of the feeder 40 and the mixer 50.

(Explanation of Feeder)

The feeder 40 of this example is provided with a raw water flangeportion 46 serving as an introduction port of water and chemicalintroduction assemblies 44A and 44B. The chemical introductionassemblies 44A and 44B are provided with chemical introduction ports 45Aand 45B for receiving the acid solution and chlorine-based solution,respectively. In a drum portion 43 of the feeder 40, a movable valve(movable part) 48 is provided. The movable valve (movable part) 48 isurged toward a tip end portion 483 of the movable valve 48 by a coilspring 482.

When the raw water I is supplied under pressure, the movable valve(movable part) 48 moves so that the raw water I is allowed to flow inthe first flow path 6 and the second flow path 7 by the compression ofthe coil spring 48 under the pressure of raw water received by a surface481 (imaginary line in FIG. 3, open position). The coil spring 482 isfixed to the drum portion 43 by an end cap 484. This end cap 484 isformed with a leak hole 485 to let the back pressure of the movablevalve 48 escape into the atmosphere.

In the vicinity of the first and second flow paths 6 and 7 thus secured,the water flow is throttled, so that the flow velocity of water flowincreases, and hence the acid solution and chlorine-based solution areintroduced through check valves 442A and 442B of the chemicalintroduction assembly 44A in accordance with Bernoulli theorem. When themovable valve 48 is at an open position, both of the check valves 442Aand 442B are in an open state. Since the feed positions correspond tothe feeding portions 41 and 42 in FIG. 1, in FIG. 2 as well, the samereference numerals are used and the feed positions are indicated as thefeeding portions 41 and 42.

At this time, the raw water 1 supplied from the raw water flange portion46 flows, in the mixer 40, dividedly in the first flow path 6 defined asone side of a separation wall 47 and the second flow path 7 defined asthe other side of the separation wall 47. In FIGS. 2 and 3, the firstflow path 6 and the second flow path 7 are indicated as the upper sideand the lower side of the separation wall 47, respectively. To the waterflows in these flow paths, the acid solution and chlorine-based solutionare fed from the two chemical introduction assemblies 44A and 44B,respectively. The acid solution and chlorine-based solution flowingthrough the first flow path and the second flow path, respectively, donot mix with each other in the feeder. Thus, in the feeder 40 of thisexample, the first flow path and the second flow path are provided, andthe acid solution and chlorine-based solution are fed to the water flowsin these flow paths and are diluted within separated streams. Feeding isaccomplished by a negative pressure occurring according to the flowvelocity of water flow, so that a pump dedicated to feeding the acidsolution and chlorine-based solution is not needed.

Also, in this example, the movable valve 48 is arranged so that when thesupply pressure of the raw water I is lower than a predetermined value,the tip end portion 483 thereof shuts off the first flow path 6 and thesecond flow path 7 (solid-line position in FIG. 3, closed position). Atthis time, the check valves 442A and 442B of the chemical introductionassemblies 44A and 44B are further pushed in by the tip end portion 483of the movable valve 48, so that the acid solution and chlorine-basedsolution are shut off from the first flow path 6 and the second flowpath 7, respectively. Thereby, when the supply pressure of the raw water1 is lower than a constant pressure, not only the raw water is shut offbut also the feeding of acid solution and chlorine-based solution isshut off. The dilute acid solution and dilute chlorine-based solution,which have been diluted in the feeding portion 41 and the feedingportion 42 in the first flow path 6 and the second flow path 7,respectively, pass through a skirt portion 49 with an opening taperangle of 8 degrees to decrease the flow velocity, and then flow out tothe mixer 50 connected to the downstream side of the feeder 40.

(Explanation of Chemical Introduction Assembly)

The chemical introduction assembly 44A, 44B (hereinafter, collectivelyindicated as 44) combined with the feeder 40 includes a cylindrical drumportion 440, the chemical introduction port 45, the check valve 442, theflow rate regulating screw 444, and the 0-ring 446 for the flow rateregulating screw 444(Figure 4). The cylindrical drum portion 440 isfitted threadedly with the chemical introduction port 45. The chemicalintroduction port 45 contains a flow path therein. The chemical sentthrough this flow path is introduced into a flow rate regulating screwcontaining portion provided in the drum portion 440, and flows in achemical flow path 447 extending along the axis of the drum portion 440.The flow rate regulating screw 444 is screwed in the drum portion 440 soas to be capable of regulating the flow rate of chemical in the chemicalflow path 447 by a tip end portion 445 of the flow rate regulating screw444 by turning the screw, and is sealed by the suitable O-ring 446. Thechemical, such as acid solution and chlorine-based solution, flowing inthe chemical flow path 447 flows into the check valve 442, and flows outof a chemical flow path 449 in the check valve 442. The check valve 442is configured so that when the tip end portion 483 (FIG. 3) of themovable part 48 pushes in a tip end portion 448 of the check valve 442,an opening/closing portion 446 formed between the check valve 442 andthe drum portion 440 is shut off, by which the flow path for thechemical is shut off.

(Explanation of Mixer)

Also, the mixer 50 in this example receives solutions diluted asdescribed above of acid solution and chlorine-based solution (FIGS. 2and 3). For the mixer 50, a pipe portion 51 is connected to an outflowport of the feeder 40 by the connecting portion 59 in such a manner thatthe liquid does not leak. In the pipe portion 51, a mixing blade body 52having many mixing blades 53 is provided. The mixing blade body 52 isarranged so that the position thereof is fixed with respect to the pipeportion 51. By a structural feature, described later, the individualmixing blades 53 cause turbulence in the water flow, by which thesolutions are strongly mixed so that the concentration of solute etc. isuniform.

(Construction of Blade of Mixer)

For the mixer 50, which is an example of the mixer, the mixing bladebody 52 is made of a plate member. This plate member extends in thelengthwise direction of the pipe portion 51, and has a width that isaccommodated in the inside diameter of the pipe portion 51. The platemember is first fabricated into a shape having constricted parts at afixed lengthwise intervals (refer to FIG. 5(A)). This fabrication can beaccomplished by using an arbitrary fabricating means (for example,punching). In this example, as the plate member, one stainless steelsheet with a thickness of 2 mm is used. Next, the plate member of thisshape is twisted at the constricted parts with the lengthwise directionbeing the axis of twisting (refer to FIG. 5(B)). Thereby, the mixingblade body 52 having a plurality of mixing blades 53 connected to eachother by connecting parts 54 as shown in FIG. 3 is manufactured.

The mixing blades 53 of the mixing blade body 52 are arranged so that amain surface 531 of the mixing blade 53 extends along the water flow inthe mixer, and the mixing blade 53 itself is not directed slantwise withrespect to the flow. However, when the mixing blades 53 are arranged inthe water flow, a Karman vortex street is formed on the downstream sideof water flow (FIG. 5(C)). This Karman vortex street is produced insuccession with time and flows to the downstream side together with thewater flow, and the individual vortex itself is not fixed at a givenposition. The vortex street continues to be formed in succession on thedownstream side of the mixing blade 52. This Karman vortex street has aproperty that the time period of formation becomes short as the flowvelocity of water flowing there increases. Further, when the flowvelocity of water flow increases, the Karman vortex street changes to analmost complete turbulent flow. In this example, the operation pressureof the movable valve 48 is set so that at least the Karman vortex streetis formed in the case where the water supply pressure is such that themovable valve 48 is at an open position.

The directions of the individual mixing blades 53 forming the Karmanvortex street are different (FIG. 5(B)). Therefore, the water flow inthe pipe 51 of the mixer 50 is fully mixed at any given cross-sectionalposition in the pipe 51 of the water flow. The same is true for the casewhere the flow velocity is higher and a turbulent flow is formed.

Although this example discloses a particular material, manufacturingmethod, and shape of the mixer, the material, manufacturing method, andshape thereof can be changed. For example, the mixing blade body of thesame shape can be made of a plastic. Also, regarding the change ofmanufacturing method, for example, the mixing blade body of the sameshape can be made by machining. Also, regarding the change of shape, inplace of the mixing blades twisted so as to have a fixed angulardifference as shown in this example, the mixing blades can take a shapesuch as to have a random angular difference. Also, the shape ofindividual blade may be, for example, circular or triangular in crosssection, not being the plate shape as in the above-described example.Anyway, any mixing blade body in which the directions of the mixingblades are different so that each mixing blade produces a substantiallyturbulent flow in the water flow can be used as the means of the presentinvention.

By the feeder and mixer of the above-described examples, an apparatusfor manufacturing sterilizing water, which can manufacture sterilizingwater stably using the feeder capable of feeding three liquids and has asimple construction, could be manufactured.

[Second Embodiment]

Another embodiment of the present invention will be described. FIG. 6 isa schematic system view of an apparatus 101 for manufacturingsterilizing water in accordance with another embodiment of the presentinvention.

In the apparatus 101 for manufacturing sterilizing water, as in theapparatus 100 for manufacturing sterilizing water, the raw water I issucked and supplied under pressure by the suitable pump 11, and to thesupplied raw water 1, the acid solution 21 is fed from the acid tank 2to form the dilute acid solution, and further the chlorine-basedsolution 31 is fed from the chlorine-based solution tank 3, by whichsterilizing water is manufactured.

In this embodiment, unlike the above-described first embodiment, the rawwater 1 flows in a series of flow path, not in plural flow paths. Theacid solution 21 and the chlorine-based solution 31 are fed in thisorder to the raw water I flowing in the flow path. The acid solution 21is fed to the raw water in a feeding portion 410 and diluted, by whichthe dilute acid solution is yielded, and then the chlorine-basedsolution 31 is fed in a feeding portion 420. The sterilizing water ismixed in the mixer 5 provided on the downstream side of the feedingportions 410 and 420, by which the sterilizing water 81 containingwater, acid solution, and chlorine-based solution is manufactured. As inthe above-described first embodiment, the tank 8, the liquid levelsensor 9, and the control means 10 are used, and the pump 11 iscontrolled by the control means 10. In the second embodiment, both ofthe aforementioned feeding portions 410 and 420 are provided in a feeder400.

(General Explanation of Example)

Next, an example of the feeder 401 that realizes this embodiment will beexplained with reference to FIG. 7. FIG. 7 is a sectional view showingconstructions of the feeder 401 of this example and the mixer 50. Thefeeding portion 410 in which the acid solution is fed corresponds to theoutlet of the chemical introduction assembly 44, and the feeding portion420 in which the chlorine-based solution is fed corresponds to theoutlet of a tip end portion 408 of a movable valve 403.

(Explanation of Feeder)

The feeder 401 is provided with the raw water flange portion 46 servingas an introduction port of water and chemical introduction assemblies 44and 404. The chemical introduction assembly 44 is constructed in thesame way as the chemical introduction assembly 44A explained in theabove-described example. The chemical introduction assembly 404 has nocheck valve, and is attached to a drum portion 402 of the feeder 401 tointroduce the chemical into the movable valve (movable part) 403provided in the drum portion 402.

When the raw water 1 is supplied, as in the above-described example, themovable valve (movable part) 403 compresses a coil spring 406 under thepressure of raw water received by a surface 405. At this time, ashoulder portion 407 of the movable valve 403 is arranged at a positionsuch as not to shut off the flow path, so that the acid solution is fedfrom the tip end portion of the check valve 442 of the chemicalintroduction assembly 44. Also, the tip end portion 408 of the movablevalve 403 is arranged at a position separated from a movable valvestopper 409, so that the chlorine-based solution is fed from a chemicalflow path 414 formed in the movable valve 403 (imaginary line in FIG. 7,open position).

The movable valve 403 is provided with the chemical flow path 414 in thecentral portion thereof. The chemical introduced from the chemicalintroduction assembly 404 flows in the chemical flow path 414, and flowsout of the tip end of the movable valve 403. In the vicinity of the tipend portion of the check valve 442 of the chemical introduction assembly44 and in the vicinity of the outlet of the chemical flow path 414, theacid solution and the chlorine-based solution are sucked by the waterflow and fed to the water flow. The positions at which the chemicals arefed correspond to the feeding portions 410 and 420 in FIG. 1, so that inFIG. 7 as well, the feeding portions are indicated by the same referencenumbers 410 and 420.

Inside the feeder 401 of this example, a series of flow paths for waterflow are provided. In the feeder 401, the acid solution is first fed tothe water and diluted, and on the downstream side, the chlorine-basedsolution is fed. These chemicals are fed by suction utilizing a negativepressure produced by the water flow and diluted. As in theabove-described first embodiment, since the acid solution andchlorine-based solution can be fed to the water flow by the negativepressure, a pump dedicated to feeding the acid solution andchlorine-based solution is not needed.

Also, in this example as well, when the supply pressure of the raw water1 is lower than a predetermined value, the movable valve (movable part)403 is urged by the coil spring 406, so that the tip end portion 408 ofthe movable valve 403 shuts off the flow path for the chlorine-basedsolution, and the shoulder portion 407 of the movable valve 403 shutsoff the flow path for acid solution in cooperation with the check valve442 (solid-line position in FIG. 7, closed position). The operations ofthe chemical introduction assembly 44 and the check valve 442 providedtherein are the same as those in the above-described example. The tipend of the movable valve stopper 409 fits in the outlet of the chemicalflow path 414 in the tip end portion 408 of the movable valve 403, sothat the chlorine-based solution does not flow out of the chemical flowpath 414. Thus, when the supply pressure of the raw water I is lowerthan a constant value, not only the supply of raw water is shut off, butalso the supply of acid solution and chlorine-based solution is alsoshut off.

The objects, constructions, and operations of the chemical introductionassembly 44 and the mixer 50, which are used in this example, are thesame as those in the above-described example.

By using the feeder and mixer of these examples, an apparatus formanufacturing sterilizing water having a series of flow path shown inFIG. 6, which uses the feeder capable of feeding three liquids and has asimple construction, could be manufactured. Thereby, sterilizing watercould be manufactured stably and easily.

[Third Embodiment]

Next, the case where the concentration of chlorine-based solution ischanged in the apparatus for manufacturing sterilizing water inaccordance with the present invention will be explained.

In this embodiment, the properties of sterilizing water were studied bychanging the concentration of chlorine-based solution by changing thedilution ratio thereof. In the present invention, as the chlorine-basedsolution before dilution, a sodium hypochlorite solution with aconcentration of 12% was used, and as the apparatus for manufacturingsterilizing water, an apparatus having a system shown in FIG. 1 andbeing provided with the feeder and mixer of the examples shown in FIGS.2 and 3 was used.

The final concentration of chlorine-based solution and the sterilizationpower at each concentration were evaluated for each dilution ratio asgiven in Table 1. TABLE 1 Dilution ratio (times) 12000 1200 400 300  100Concentration (ppm)   10  100 300 400 1200 Sterilization power NormalEnough Enough Strong Strong

As the sterilization power, an indicator of sterilization power used inthe field of foods is shown. The indicator of “normal” indicatessterilization power corresponding to a chlorine concentration of 1000ppm in the case where the liquid properties are not adjusted by an acidsolution. “Enough” indicates sterilization power higher than the normalpower, which was high enough for the sterilizing water to be applied tothe field of foods. Also, “strong” indicates sterilization power havinga strength that would not be usually needed in the field of foods.

The sterilizing water thus manufactured, in which the concentration ofsodium hypochlorite was 1200 ppm, emitted a strong chlorine odor at thetime of actual use, so that it was unsuitable for applications in whichit was used for long-term work. The reason for this was that in theapparatus for manufacturing sterilizing water in accordance with thepresent invention, a water flow including some heterogeneity was mixedwith acid solution and chlorine-based solution by the mixer. Thereby,the manufacturing conditions of sterilizing water were somewhat varied,and a chlorine odor was noticed, for example, especially at the time ofopening/closing of the movable valve 48.

Contrarily, the sterilizing water with sodium hypochloriteconcentrations of 100, 300 and 400 ppm had no chlorine odor and could beused in applications in which it was used for long-term work. Also, thesterilizing water with a sodium hypochlorite concentration of 10 ppmexhibited sterilization power of almost the same degree as theconventional case of 1000 ppm concentration in which the liquidproperties were not regulated by acid solution, but it had a weakchlorine odor and was useful, for example, in an application in whichsterilization was accomplished by long-term immersion.

[Fourth Embodiment]

Still another embodiment of the present invention will be explained.FIG. 8 is a system diagram showing a configuration of an apparatus 103for manufacturing sterilizing water in accordance with one embodiment ofthe present invention. In this embodiment, separate feeders are used forfeeding the acid solution and chlorine-based solution.

In the apparatus 103 for manufacturing sterilizing water, the raw water1 is supplied under pressure by suitable means. The water flow of theraw water 1 is divided into two water flows. For one water flow, theacid solution 21 is fed to the water flow from the acid solution tank 2by an acid solution feeder 26, and the dilute acid solution (acidicwater) is stored in a dilute acid solution tank 27. For the other waterflow, the chlorine-based solution 31 is fed to the water flow from thechlorine-based solution tank 3 by a chlorine-based solution feeder 36,and the dilute chlorine-based solution is stored in a dilutechlorine-based solution tank 37. On the suction side of the pump 11, asuction water path 460 is installed. This suction water path 460 has twosuction ports, and the suction ports each are arranged in the diluteacid solution tank 27 and the dilute chlorine-based solution tank 37.The dilute acid solution and the dilute chlorine-based solution aresucked through the suction ports, and are joined together in a joiningportion 415. An acid solution mixer 29 and a chlorine-based solutionmixer 39 are provided between the pump and the acid solution feeder 26and between the pump and the chlorine-based solution feeder 36,respectively.

FIG. 8 shows one example of such an arrangement. In the suction waterpath 460 shown in FIG. 8, the acid solution mixer 29 and thechlorine-based solution mixer 39 are arranged in the water paths betweenthe suction port and the joining portion 415, and a joining mixer 56 isprovided between the joining portion 415 and the pump 11. Thesterilizing water manufactured by joining is taken out through a faucet(not shown) etc. provided in the water path on the downstream side ofthe pump.

Next, apparatuses 105, 106 and 107 for manufacturing sterilizing waterhaving other configurations in this embodiment will be explained withreference to FIGS. 16 and 17. FIG. 16(a) shows the apparatus 105 formanufacturing sterilizing water, in which a raw water tank 16 is used inthis embodiment, and a water flow to which the acid solution is fed anda water flow to which the chlorine-based solution is fed are supplied byusing raw water pumps 13 and 15, respectively. If the apparatus formanufacturing sterilizing water is configured in this manner, the waterflows to which the acid solution 21 and the c chlorine-based solution 31are fed are controlled by the pumps 13 and 15, respectively. Thereby, inthe case where the supply pressure of raw water fluctuates, for example,even if the raw water is, city water, the acid solution 21 and thechlorine-based solution 31 are fed stably, so that the manufacturingprocess of sterilizing water is stabilized. Also, as shown in theapparatus 106 for manufacturing sterilizing water shown in FIG. 16(b),the positions of the raw water pumps 13 and 15 may be on the downstreamside of the feeders 26 and 36 for acid solution and chlorine-basedsolution. If a plurality of raw water pumps are used, a feedingoperation matching the acid solution and chlorine-based solution can beperformed. Further, as shown in the apparatus 107 for manufacturingsterilizing water shown in FIG. 17, only one raw water pump may be usedbefore the raw water flow 1 is divided, not using the plural raw waterpumps.

In this embodiment, an arrangement other than the arrangement of theacid solution mixer 29 and the chlorine-based solution mixer 39 shown inFIG. 8 can be used. Specifically, the acid solution mixer 29 can beprovided between the acid solution feeder 26 and the dilute acidsolution tank 27, and the chlorine-based solution mixer 39 can beprovided between the chlorine-based solution feeder 36 and the dilutechlorine-based solution tank 37. For example, in the apparatus 105 formanufacturing sterilizing water shown in FIG. 16(a), the acid solutionmixer 29 and the chlorine-based solution mixer 39 are arranged on thedownstream side of the dilute acid solution tank 27 and the dilutechlorine-based solution tank 37, respectively, but in the apparatus 106for manufacturing sterilizing water shown in FIG. 16(b), these mixersare arranged on the upstream side of the tanks.

For the acid solution 21, the feeding rate thereof to the water flow iscontrolled by a negative pressure produced by the water flow in the acidsolution feeder 26 and restriction of flow rate due to a flow raterestricting orifice of the regulator 22. The feeding rate of the acidsolution 21 is monitored by a flow sensor 24. The output of the flowsensor 24 is connected to a computer (not shown) to check whether or notthe feeding rate is not higher than the upper limit value. For thechlorine-based solution as well, the feeding rate thereof is restrictedby a regulator 32, and the feeding rate is monitored by a flow sensor34. The chlorine-based solution is fed by being controlled by a negativepressure produced by the water flow in the chlorine-based solutionfeeder 36 and the regulator 32.

In the configuration shown in FIG. 8, since the dilute acid solutiontank 27 and the dilute chlorine-based solution tank 37 store dilutesolutions produced on the upstream side of these tanks, the pressureproduced by the water flow on the upstream side is released once inthese tanks. Therefore, the feeding rate of acid solution and thefeeding rate of chlorine-based solution depend on the water pressure ofthe raw water 1. Also, the degrees of mixing in the acid solution mixer29 and the chlorine-based solution mixer 39 depend on the water flowproduced by the pump 11. Therefore, for example, even if the quantity ofsterilizing water consumed is varied by the opening/closing of thefaucet on the downstream side of the pump 11, the concentration ofdilute acid solution and the concentration of dilute chlorine-basedsolution do not change due to the feeding of acid solution and thefeeding of chlorine-based solution.

A suitable liquid level sensor, not shown, can be used for the diluteacid solution tank 27 and the dilute chlorine-based solution tank 37,and an electromagnetic valve etc. can be provided at a position betweenthe division point of the raw water 1 and the acid solution feeder 26and the chlorine-based solution feeder 36, by which the quantities ofdilute acid solution and dilute chlorine-based solution can becontrolled according to the position of liquid level sensor by suitablecontrol. By this control, for example, a changeover between the state offlow rate capable of properly performing feeding and the state in whichno water flow is present can be carried out. That is to say, thequantity of sterilizing water consumed through the faucet need notnecessarily be reflected directly, and simple control of ON/OFF only canbe carried out. This electromagnetic valve may further be restricted bythe feeding rate detected by the flow sensors 24 and 34.

The raw water 1 is not subject to any special restriction, and purewater, city water, river water, underground water, and the like can beused according to the situation. As the acid solution 21, hydrochloricacid (hydrogen chloride solution) with a suitable concentration (forexample, 8.5%), acetic acid, and the like are used. Also, as thechlorine-based solution 31, sodium hypochlorite solution with a suitableconcentration (for example, 12%), chlorine dioxide, and the like areused.

[Fifth Embodiment]

Still another embodiment of the present invention will be explained.FIG. 9 is a system diagram showing a configuration of an apparatus 104for manufacturing sterilizing water in accordance with one embodiment ofthe present invention. In FIG. 9, the same reference numerals areapplied to the same elements as those in FIG. 8 etc.

In the apparatus 104 for manufacturing sterilizing water as well, theraw water 1 is supplied under pressure by suitable means. In thisembodiment, the water flow of the raw water 1 is not divided. The acid21 is fed from the acid solution tank 20 by the acid solution mixer 26to yield the dilute acid solution, which is stored in the dilute acidsolution tank 27. The dilute acid solution is sucked by the pump 11 toform a water flow. The chlorine-based solution 31 is fed to this waterflow by the chlorine-based solution feeder 36, and the water flow ismixed homogeneously by the chlorine-based solution mixer 39, by whichsterilizing water is manufactured. The faucet, not shown, etc. areprovided on the downstream side of the pump 11, so that the sterilizingwater is consumed through the faucet etc. The acid solution mixer 29 isarranged at any position in the water path between the acid solutionfeeder 26 and the chlorine-based solution feeder 36. In FIG. 9, it isarranged between the dilute acid solution 27 and the chlorine-basedsolution feeder 36.

In the configuration shown in FIG. 9, since the dilute acid solutiontank 27 stores a dilute solution produced on the upstream side of thetank, the pressure produced by the water flow on the upstream side isreleased once in this tank. Therefore, the feeding rate of acid solutiondepends on the water flow (water pressure) of the raw water 1. Also, thewater flow caused by suction accomplished by the pump 11 exerts aninfluence on the feeding rate of the chlorine-based solution 31 and thedegrees of mixing in the acid solution mixer 29 and the chlorine-basedsolution mixer 39. Even if the quantity of sterilizing water consumed isvaried by the opening/closing of the faucet on the downstream side ofthe pump 11, the concentration of dilute acid solution does not changedue to the feeding of acid solution.

Also, apparatuses 108 and 109 for manufacturing sterilizing water havingother configurations of this embodiment are explained with reference toFIG. 18. These apparatuses 108 and 109 for manufacturing sterilizingwater show examples in which the raw water tank 16 is used. In theapparatus 108 for manufacturing sterilizing water shown in FIG. 18(a),the raw water pump 13 sucks the raw water from the raw water tank 16 forforming a water flow, and the acid solution 21 is fed to this waterflow. The dilute acid solution is stored in the dilute acid solutiontank 27. Thus, the acid solution is fed to the water flow that iscontrolled by the raw water pump 13, so that even if the source of rawwater is city water etc. (not shown), stable feeding of acid solution isrealized. The manufactured sterilizing water is stored in thesterilizing water tank 8, and is taken out of the sterilizing water tankby a pump 57 as necessary. In the apparatus 109 for manufacturingsterilizing water shown in FIG. 18(b), the raw water pump 13 is arrangedon the downstream side of the acid solution feeder 26. In this case aswell, the same effects as those in the apparatus shown in FIG. 18(a) areachieved.

A suitable liquid level sensor etc. are used for the dilute acidsolution tank 27, and an electromagnetic valve etc. are provided on theupstream side of the acid solution feeder 26, by which the quantity ofdilute acid solution can be controlled by suitable control. The quantityof sterilizing water consumed through the faucet need not necessarily bereflected directly in this control. The regulators 22 and 32, the flowsensors 24 and 34, the electromagnetic valve, the control methodthereof, and the like are the same as those in the fourth embodiment.

[Sixth Embodiment]

An apparatus 110 for manufacturing sterilizing water in accordance withstill another embodiment of the present invention will be explained withreference to FIG. 19. In this apparatus 110 for manufacturingsterilizing water, the dilute acid solution tank 27 is not used, and theraw water tank 16 is used. The position of the raw water pump 13 is notsubject to any special restriction. The raw water pump 13 may be locatedjust on the downstream side of the raw water tank, on the downstreamside of the acid solution mixer 29 as shown in FIG. 12, or on thedownstream side of the chlorine-based solution mixer 39. Without the useof the dilute acid solution tank 27, the use of the raw water tankrealizes the stable feeding of acid solution and chlorine-based solutionand hence enables stable manufacture of sterilizing water even if theraw water is city water etc. (not shown) whose pressure fluctuates. Thesterilizing water thus manufactured is stored in the sterilizing watertank 8, and is consumed by being taken out by the pump 57 etc. asnecessary.

[Seventh Embodiment]

Still another embodiment of the present invention will be explained.FIG. 10 is a system diagram showing a configuration of an apparatus 105for manufacturing sterilizing water in accordance with one embodiment ofthe present invention. In this embodiment, the dilute acid solution tank27 and the dilute chlorine-based solution tank 37 are removed from theapparatus 103 for manufacturing sterilizing water (FIG. 8), and thesterilizing water tank 8 is used after the manufacture of sterilizingwater.

The advantages of the apparatus 105 for manufacturing sterilizing waterover the apparatus 103 for manufacturing sterilizing water are asfollows: the raw water 1 need not necessarily be supplied under pressurefrom the upstream side, and the manufacturing conditions are notaffected by the usage of sterilizing water because the mixing situationafter the feeding of acid solution and chlorine-based solution to thewater flow or the dilution thereof for the manufacture of sterilizingwater and the usage of sterilizing water are independent from eachother.

In FIG. 10, a suitable liquid level sensor etc. is used for thesterilizing water tank 8, and an electromagnetic valve etc. is providedin front of the division point of path of the raw water 1, by which thequantity of dilute acid solution can be controlled by suitable control.The quantity of sterilizing water consumed through the faucet need notnecessarily be reflected directly in this control. The regulators 22 and32, the flow sensors 24 and 34, the electromagnetic valve, the controlmethod thereof, and the like are the same as those in the fourth andfifth embodiments.

EXAMPLE

A more detailed example and a modification thereof of the apparatus 105for manufacturing sterilizing water described in the seventh embodimentwill now be described with reference to FIGS. 11 to 15.

FIG. 11 is a partially sectional plan view showing a construction of anassembly from the water path 12 to the joining mixer 56 in the exampleof the apparatus 105 for manufacturing sterilizing water. FIG. 12 is apartially sectional side view of the assembly shown in FIG. 11.According to the construction of this example, the chemicals (FIG. 12shows only the chlorine-based solution 31) are fed to and mixed with theraw water 1, by which the sterilizing water 81 is manufactured.

The water path 12 is divided, and the water flows 6 and 7 enter the acidsolution feeder 26 and the chlorine-based solution feeder 36,respectively. On the downstream side of the feeders, the acid solutionmixer 29 and the chlorine-based solution mixer 39 are connected, and thewater flows 6 and 7 join together in the joining portion 415. On thedownstream side of the joining portion 415, the joining mixer 56 isconnected.

The acid solution mixer 29 and the chlorine-based solution mixer 39 havetubes 291 and 391 each serving as a water path, respectively. In thetube, mixing elements 292 are provided so as to be in contact with theinside of the tube. The mixing elements 292 are arranged in a pluralnumber in the direction of the axis of the tubes 291 and 391 for formingthe water flow.

(Construction of Feeder)

As shown in a partial cross section in FIG. 12, the feeder is a feederutilizing the flow velocity of water flow. The water flow is throttledonce, and the chemical (in FIG. 12, the chlorine-based solution 31) ofthe quantity according to the water flow is fed to the water flow by anegative pressure produced by the water flow which has been throttledand increased in velocity. In this water path for feeding, a check valve33 is provided. The check valve 33 prevents the raw water from flowingto the chemical side even if the pressure on the water flow side becomeshigher than that on the chemical side for any reason.

(Construction of Mixing Element)

As shown in FIG. 13, each of the mixing elements 292 has a convexportion 296 and a concave portion 298 of a joint having a hexagonalcross section. The convex portion 296 and the concave portion 298 of theadjacent mixing elements are fitted to each other (FIGS. 11 and 12), andthe angular difference around the axis is kept. Since the joint has ahexagonal cross section, in this example, the angular difference betweenthe adjacent mixing elements is a multiple of 60 degrees.

The concave portion 298 of the joint has a shape of hexagonal prism.However, the convex portion 296 is not of a prismatic shape, though thecross section thereof is a hexagonal shape, and has a flexibleconstruction such that the direction thereof can be changed freely tosome extent so as to match the bend of the tubes 291 and 391 while beingfitted to the concave portion 298. In this example, the convex portion296 has a shape such as to be the tip end portion of a ball-pointed typehexagonal wrench. Thereby, even when the arrangement direction of themixing elements 292 is bent along the bend of tube, the angulardifference between the adjacent mixing elements is kept in the same wayas the case where the tube is not bent. Although the joint of mixingelement in this example is manufactured so as to have a hexagonal crosssection, the joint may have a cross section of triangular, square, orthe like shape. In particular, a regular polygon having an arbitrarynumber of sides is preferable.

The mixing element 292 has a block rod substantially protruding into theflow. In FIG. 13, this block rod 294 has a cross section of a circularshape. The block rod 294 has an operation for generating Karmanvortexes, and hence generating a substantially turbulent flow in theflow in the tube. Although the block rod 294 can have a shape other thanthe circular cylinder, circular cylinder is favorable because itgenerates a turbulent flow efficiently and has low resistance.

In the mixing element 292 of this example, the block rod 294 protrudesin four directions, but it is not necessarily required to protrude infour directions. In order to achieve stronger mixing, a larger number ofblock rods can be used. Conversely, a smaller number of, for example,three block rods can be used. Since the block rod 294 protrudes in fourdirections and the joint has a hexagonal shape, if the adjacent mixingelements 292 are fitted to each other so as to shift by 60 degrees, theblock rods of the adjacent mixing elements are also arranged so as toshift by 60 degrees. Thereby, as the flow in the tubes 291 and 391passes through the plural mixing elements, the block rods 292 act onvarious portions of the flow, by which satisfactory mixing is realized.FIGS. 11 and 12 show the state in which the mixing elements 294 arearranged at various angles.

(Construction of Regulator)

Also, the regulator 32 (FIGS. 12 and 14) includes a turret portion 324,which is provided rotatable around the rotation center 321 and isprovided with a plurality of flow rate restricting orifices 326 havingdifferent inside diameters (in FIG. 14(b), 0.3 to 1.0 mm in diameter),and a turret receiving portion 322, which has a flow path 323 aligningwith any of the flow rate restricting orifices 326. The turret receivingportion 322 has a flow path 327 connected to the chlorine-based solutiontank 30 (not shown in FIGS. 12 to 15). The chlorine-based solution flowsinto the regulator 32 through the flow path 327, entering a recessportion 328 in the turret portion, and flows out to the flow path 323after passing through the orifice aligning with the flow path 323 of theflow rate restricting orifices.

An O-ring groove 325 is provided around the turret portion 324, and anO-ring (not shown) is fitted in the O-ring groove 325. In this state,the turret portion 324 is inserted into the turret receiving portion322. The turret portion 324 is pressed against the turret receivingportion 322 by a spring 329 (FIG. 12) to maintain airtightness. However,the turret portion 324 can be turned around the rotation center 321without a heavy burden imposed on the O-ring. By turning the turretportion 324, the flow rate restricting orifice used can be selectedappropriately.

In FIG. 12, a flow path 330 is interposed between the regulator 32 andthe chlorine-based solution feeder 36. In a modification of thisexample, in place of the flow path 330, the flow sensor 34 can be used.As the flow sensor 34, for example, a flow sensor shown in FIG. 15 canbe used.

The flow sensor 34 shown in FIG. 15 is manufactured so that acylindrical piston member 340, which is made of a material having lighttransmitting properties, can be moved vertically in the figure. Acylinder portion 341, which has a cylindrical inside side surface withan inside diameter slightly larger than the diameter of the cylindricalportion of the piston member, holds the piston member 340. The cylinderportion 341 is provided with a plurality of minute holes 342. The minuteholes 342 are provided in one row as being arranged in a straight lineform in the figure. However, the minute holes 342 may be arranged inother ways.

The cylinder portion 341 and the piston member 340 separate a frontchamber 343 from the rear chamber 344. However, the front chamber 343and the rear chamber 344 are connected to each other by the pluralminute holes 342.

The piston member 340 is provided with a light intercepting member 345,which moves along with the movement of the piston member 340.

A light emitting element 346 is a light emitting element that emits asuitable light, such as a red light emitting diode, and is arranged sothat the emitted light forms a light path 348 in the range in which thelight intercepting member 345 moves together with the piston member 340.

A light receiving element 347 is provided so as to receive the light ofthe light emitting element 348, and is arranged so as to be capable ofdetecting that the light intercepting member 345 intercepts the lightpath 348.

The rear chamber 344 is covered with an external cylinder member 349having light transmitting properties, so that the detection of positionof the light intercepting member 345 due to light is not hindered.

This flow sensor 34 is used in an orientation such that when a movablemember moves downward due to the gravity, the minute holes 342 areclosed.

The movable member consisting of the light intercepting member 345 andthe piston member 340 closes at least some minute holes 342 if adifferential pressure obtained by subtracting the pressure of a workingfluid in the rear chamber 344 from the pressure of a working fluid inthe front chamber 343 is not higher than a predetermined pressure(working pressure). Depending on the arrangement of the minute holes342, all or only some of the minute holes 342 may be closed.

The working pressure by which the movable member is moved is defined asa difference in pressure (differential pressure) between the pressure inthe front chamber 343 and the pressure in the rear chamber 344, forexample, such as to give an upward force that is the same as a downwardforce obtained by removing a buoyancy exerted on the movable member bythe working fluid from the gravity due to the mass of the movablemember. In this example, preferably, the materials of the piston member340 and the light intercepting member 345 are selected so that thedownward force remains according to the gravity even if the buoyancy ofthe working fluid acts, that is, the movable member has a greaterspecific gravity than the working fluid.

Also, if the differential pressure becomes higher than the workingfluid, the moving member is displaced upward according to thedifferential pressure, and operates so that the closed minute holes 342are opened in succession, and thereby a larger quantity of working fluidis caused to flow from the front chamber to the rear chamber. Since theminute holes connect the front chamber 343 to the rear chamber 344, ifmore minute holes are opened, the working fluid flows through the minuteholes so as to eliminate the differential pressure. Thereby, theconductance of fluid between the front chamber 343 and the rear chamber344 is increased, and varies in the direction such that the differentialpressure is eliminated. For example, if the differential pressurebecomes equal to the working pressure that causes the movement ofmovable member, the movable member does not move further. Thus, the flowsensor 34 of this example can detect the flow rate of working fluid viathe displacement of movable member caused by the differential pressure.

When the light intercepting portion 345 of the movable member that isdisplaced by a change in differential pressure intercepts the light path348, the quantity of detected light received by the light receivingelement is changed thereby, and this change is output as an outputsignal. This output signal is input in, for example, a computer (notshown), and is monitored. Thereby, for example, if the feeding rate ofchlorine-based solution exceeds a predetermined value, anelectromagnetic valve (not shown) provided at a suitable position iscontrolled accordingly, and thereby the manufacture of sterilizing watercan be stopped.

It is a matter of course that the sensitivity and application range offlow sensor can be set suitably by appropriately adjusting thearrangement and sizes of the minute holes 342 or by appropriatelyadjusting the positions of the light emitting element 346 and the lightreceiving element 347 as indicated by arrow marks 352 and 353 in FIG.15. Also, in FIG. 15(b), an inlet 350 and an outlet 351 of the flowsensor 34 are provided at the side of the flow sensor 34. However, theconfiguration can be such that the inlet 350 is provided in the bottomsurface and the outlet 351 is provided in the top surface to match theflow path 330 (FIG. 12). Also, although explanation has been given ofthe feeding and mixing of the chlorine-based solution, for the feedingand mixing of acid solution as well, the same feeder, regulator, flowsensor, and the like can be used.

[Eighth Embodiment]

FIG. 20 is a system diagram for illustrating still another embodiment ofthe present invention, in which bypass water paths are used. In thisembodiment, the bypass water path is used for each feeder. Thereby, theconcentration can be regulated to some extent even in the case where afeeder that does not have a regulating mechanism for the feeding rate ofacid solution or chlorine-based solution is used.

FIG. 20(a) shows an apparatus 111 for manufacturing sterilizing water,which realizes the water flow to which acid solution is fed and thewater flow to which chlorine-based solution is fed by separate waterpaths (first and second water paths).

The apparatus 111 for manufacturing sterilizing water includes the pump11, dividing portions 502 and 504, the acid solution feeder 26 (firstfeeder), the acid solution mixer 29, and a water path (first water path)reaching the sterilizing water tank 8 through a joining portion 532 andthe joining portion 415.

Also, the apparatus 111 for manufacturing sterilizing water has a waterpath (second water path) which has the chlorine-based solution feeder 36(second feeder) and the chlorine-based solution mixer 39 in the path,and divides from the first water path in the dividing portion 502 on theupstream side of the acid solution feeder 26 and joins again to thefirst water path in the joining portion 415 on the downstream side ofthe acid solution feeder 26.

Further, the apparatus 111 for manufacturing sterilizing water has, inaddition to the first and second water paths, a first bypass water pathwhich has a flow rate restricting valve 524 in the path, and bypassesthe first feeder by dividing from the first water path in the dividingportion 504 on the upstream side of the acid solution feeder 26 (firstfeeder) and by joining again to the first water path in the joiningportion 532 on the downstream side of the acid solution feeder 26.

In addition, the apparatus 111 for manufacturing sterilizing water has asecond bypass water path which has a flow rate restricting valve 522 inthe path, and bypasses the second feeder by dividing from the secondwater path in the dividing portion 502 on the upstream side of thechlorine-based solution feeder and by joining again to the second waterpath in the joining portion 415.

The flow rate restricting valve 524 has a function for mainly regulatingthe raw water that further dilutes the dilute acid solution having beendiluted by the feeding of acid solution. Also, the flow rate restrictingvalve 522 has a function for mainly regulating the dilution ofchlorine-based solution.

On the other hand, FIG. 20(b) shows an apparatus 112 for manufacturingsterilizing water, which realizes the water flow to which acid solutionis fed and the water flow to which chlorine-based solution is fed by aseries of water path (main water path).

The apparatus 112 for manufacturing sterilizing water has the pump 11, adividing portion 508, the acid solution feeder 26 (first feeder), theacid solution mixer 29, a joining portion 534, a dividing portion 510,the chlorine-based solution feeder 36 (second feeder), thechlorine-based solution mixer 39, and a water path (main water path)reaching the sterilizing water tank 8 through a joining portion 536. Themain water path is configured so that the raw water is introduced andthe acidic water is fed, then the chlorine-based solution is fed, andthe dilute solution having been mixed is caused to flow into thesterilizing water tank.

Also, the apparatus 112 for manufacturing sterilizing water has a firstbypass water path which has a flow rate restricting valve 526 in thepath, and bypasses the acid solution feeder 26 by dividing from the mainwater path in the dividing portion 508 on the upstream side of the acidsolution feeder 26 and by joining again to the main water path in thejoining portion 534 on the downstream side of the acid solution feeder26 and on the upstream side of the chlorine-based solution feeder 36.

Further, the apparatus 112 for manufacturing sterilizing water has asecond bypass water path which has a flow rate restricting valve 528 inthe path, and bypasses the chlorine-based solution feeder 36 by dividingfrom the main water path in the dividing portion 510 on the downstreamside of the joining portion 534 and on the upstream side of thechlorine-based solution feeder 36 and by joining again to the main waterpath in the joining portion 536 on the downstream side of thechlorine-based solution feeder 36.

The flow rate restricting valve 526 has a function for regulating theflow rate of raw water in the first bypass water path, which furtherdilutes the dilute acid solution having been diluted by the feeding ofacid solution. Also, the flow rate restricting valve 528 has a functionfor regulating the flow rate in the second bypass water path throughwhich dilute acid solution that need not be caused to flow in thechlorine-based solution feeder 36.

This embodiment, in both of the apparatuses for manufacturingsterilizing water, aims at realizing stable feeding while the flow ratesof the acid solution and chlorine-based solution are restricted,restricting the tank volumes of the acid solution tank 2 and thechlorine-based solution tank 3 by increasing the concentration of theacid solution and chlorine-based solution, or increasing the sterilizingwater capable of being manufactured with the same tank volume.

In the configurations of the apparatuses 111 and 112 for manufacturingsterilizing water, each of the feeders is a suction type feeder. In thepath for the fed liquid, an electromagnetic valve etc. can be providedas necessary to carry out simple opening/closing control, but there isprovided no mechanism for regulating the flow rate of the fed liquid.

For the suction type feeder, it is generally difficult to realize stablefeeding at a feeding rate lower than a fixed rate. Also, the feeder ofthis type has a property that if the flow rate (or flow velocity) ofwater flow increases, the suction pressure of the acid solution orchlorine-based solution increases in accordance with Bernoulli theorem,and the feeding rate also increases. The feeder in accordance with thisembodiment also has this property. For example, when the chemical is fedat a feeding rate not lower than 60 ml/min, preferably, at a feedingrate not lower than 80 ml/min, the acid solution feeder 29 andchlorine-based solution feeder 39 realize stable feeding. However, ifthe feeding rate is lower than the above-described value, stable feedingcannot be realized. Also, for the acid solution feeder 29 andchlorine-based solution feeder 39, the flow rate of water flow must benot lower than a fixed value to realize the above-described stablefeeding. For example, for a certain feeder, when the flow rate is notlower than 7 liter/min, the feeding rate of chemical is 80 ml/min, sothat the stable feeding is realized. Hereunder, for convenience ofexplanation, all feeders are assumed to be feeders of the same type asthe above-described feeder. Also, in this embodiment, since it isdesirable to make the flow rate low to restrain the consumption of theacid solution and chlorine-based solution, the operation in the casewhere the feeding rate is fixed (for example, 80 ml/min) is explained.In this case, the water flow (water flow in the first and second waterpath and the main water path) is fixed (for example, 7 liter/min) as anecessary consequence.

First, the case where sterilizing water of a quantity as small aspossible is manufactured is considered. For this purpose, in any of theapparatuses for manufacturing sterilizing water, all flow raterestricting valves in the bypass water path are fully closed. In thiscase, in the configuration of the apparatus 111 for manufacturingsterilizing water, the raw water of the sum of the minimum flow ratesfor the first and second water paths has only to be supplied by the pump11, and in the configuration of the apparatus 112 for manufacturingsterilizing water, the raw water of the minimum flow rate for the mainwater path has only to be supplied by the pump 11.

Therefore, in order to yield a small quantity of sterilizing water undera condition that the pump can regulate the flow rate freely and the samefeeder is used, the configuration of the apparatus 112 for manufacturingsterilizing water is more suitable than that of the apparatus 111 formanufacturing sterilizing water. Also, in the case where the intendedyielding quantity is larger than the yielding quantity of the apparatus112 for manufacturing sterilizing water, the regulation of dilutionaccomplished by opening the flow rate restricting valve is easier in theapparatus 112 for manufacturing sterilizing water than in the apparatus111 for manufacturing sterilizing water.

Next, the case where sterilizing water of a quantity as large aspossible is manufactured is considered. In this case, the configurationis made such that the bypass water path has low resistance. Thereby, ifthe flow rate restricting valve in the bypass water path is openedsufficiently, a large quantity of the raw water 1 can be caused to floweven if the flow rate in the feeder is still kept at the minimum rate.In this case as well, a large quantity of sterilizing water can bemanufactured by increasing the concentrations of acid solution andchlorine-based solution without changing the components of sterilizingwater. Actually, there occurs a phenomenon that if the concentration ofchlorine-based solution is too high, the sterilizing performancedecreases earlier (deactivation). Therefore, the concentration ofchlorine-based solution cannot be set freely, and also the pump has alimitation, which imposes a restriction. However, by changing the designappropriately based on the configuration of the apparatus formanufacturing sterilizing water in accordance with this embodiment, alarge quantity of sterilizing water can be manufactured with smallquantities of acid solution and chlorine-based solution.

For convenience of explanation, explanation has been given assuming thatthe feeding rates of acid solution and chlorine-based solution and thequantity of water in the feeder are fixed. Actually, however, a changein feeding rates of acid solution and chlorine-based solution increasingwith the flow rate is considered, the flow rates in the first and secondwater paths and the main water path is kept as low as possible in therange in which the flow rates are higher than the lower limit value forrealizing the stable feeding, and the valves in the bypass water pathsare regulated so that the other flow rates are caused to flow in thebypass water path. Also, since the actual pump has a functional relationbetween pressure and water quantity, regulation closer to the actualsituation can be accomplished by considering this fact.

In this embodiment, by the above-described configuration, the feeder canbe operated under a condition suitable for the feeding, and theconcentration of acid solution and chlorine-based solution can bedecreased by using the downstream bypass water path. Therefore, theoperations of feeding and dilution can be set so as to meet therespective objectives, so that the stable operation can be performed.

Furthermore, other features of this embodiment are explained. In theapparatuses 111 and 112 for manufacturing sterilizing water, a vessel 84is used in the sterilizing water tank 8. This vessel 84 is abucket-shaped vessel whose upper side is open, and is configured so asto once receive the sterilizing water 81 to be stored in the sterilizingwater tank 8 and causes the sterilizing water to overflow the vessel(arrow mark 86 in FIG. 20). The water path for causing sterilizing wateror raw water to flow into the sterilizing water tank has its outflowport disposed at an inside position lower than the top surface of thevessel 84 having a height 88 of water level at the overflow time(overflow level). Therefore, the pressure applied to the outflow port ofwater path (pressure due to water depth of sterilizing water) is fixedregardless of the quantity of sterilizing water stored in thesterilizing water tank. Thereby, the pressure applied to the outflowport is scarcely changed unless the distance from the overflow surfaceto the outflow port changes, so that a change in water pressure does notoccur regardless of the quantity of sterilizing water in the sterilizingwater tank 8. Therefore, the pressure on the downstream side of thesuction type feeder is stabilized, and hence the feeding operation inthe suction type feeder is stabilized.

Further, according to this configuration, no air intrudes from theoutflow port of water path even when the apparatus is shut down.

In the above-described apparatuses 111 and 112 for manufacturingsterilizing water, even if the raw water has different acidities (pH),the pH of dilute acidic water at the intermediate stage (for example,the pH at the outlet of the acid solution mixer 29) can be made fixed byadjusting the flow rate restricting valve. Therefore, in the case wherepH changes as actually found as a difference in water quality of citywater between regions, the apparatus for manufacturing sterilizing watercan be adjusted so as to match the difference in water quality byadjusting the flow rate restricting valve when the apparatus formanufacturing sterilizing water in accordance with this embodiment isinstalled. Also, unlike the apparatuses 111 and 112 for manufacturingsterilizing water, even in the case where the raw water is supplied bycity water without the use of the pump 11, the manufacturing conditionsfor sterilizing water can be adjusted in accordance with the supplycondition of raw water by adjusting the flow rate restricting valve inaccordance with various supply quantities and water pressures.

[Effects of the Invention]

According to the above disclosure, in the present invention, in theapparatus for manufacturing sterilizing water, in which sterilizingwater is manufactured by mixing a chlorine-based compound consisting ofsodium hypochlorite or chlorine dioxide or a combination thereof and anacid solution consisting of hydrochloric acid etc. with water, theaqueous solution of chlorine-based compound can be made weakly acidic toneutral condition without the production or dissolution of chlorine gas.The feeder in accordance with the present invention can feed the acidsolution and chlorine-based compound by a small and simple constructionbecause it feeds both of the acid solution and the chlorine-basedcompound, and also realizes stable feeding.

Also, by the feeder using vortexes or a turbulent flow, which is used inthe apparatus for manufacturing sterilizing water in accordance with thepresent invention, the concentration of sterilizing water is madeuniform. Thereby, the chlorine concentration in the sterilizing water ismade fixed, so that stable sterilization power is achieved. According tothe configuration in accordance with the present invention in which theacid solution and chlorine-based compound are fed by suction utilizing anegative pressure produced in the water flow without the use of a pump,there is no pulsation at the time of feeding, and the concentrations ofacid and chlorine in the water flow do not change with time. Inaddition, according to the configuration in which the pH of sterilizingwater of the present invention is in the range of 4.8 to 7.5, thesterilization power is enhanced, and hence high sterilization power canbe obtained by a lower concentration of chlorine-based solution.

According to the above disclosure, in the present invention, in theapparatus for manufacturing sterilizing water, in which sterilizingwater is manufactured by feeding a chlorine-based compound consisting ofsodium hypochlorite or chlorine dioxide or a combination thereof and anacid consisting of hydrochloric acid to water, the aqueous solution ofchlorine-based compound can be made weakly acidic to neutral conditionwithout the production or dissolution of chlorine gas. In the apparatusfor manufacturing sterilizing water in accordance with the presentinvention, since a tank for appropriately releasing a pressure is used,the influence exerted on the manufacturing conditions by the usagesituation of sterilizing water can be decreased, and hence sterilizingwater having stable quality can be manufactured.

In the present invention, the chemical can be fed according to the waterflow by using the water flow itself, or a static mixer can be used, sothat the sterilizing water can be manufactured by a simple apparatus.Also, by using the raw water tank or the raw water pump, the water flowcan be stabilized, so that the chemical can be fed more stably.

Also, by using the mixing elements of one shape, the flow at variouspositions in the tube can be made turbulent, and hence the mixingelements can be used at a place where the tube is bent.

Further, since a regulator that performs stable flow rate restrictingoperation can be realized, the flow rate can be controlled properly evenin the case where the acidic water and chlorine-based solution with highconcentration are fed to water little by little.

In addition, since even a minute flow can be detected stably, even atthe time of manufacture of sterilizing water, the feeding rates of theacidic water and chlorine-based solution can be detected toappropriately shut down the apparatus, so that the sterilizing water canbe manufactured safely.

If the bypass water path arranged in parallel with the feeder is used,and the flow rate restricting valve is further provided in the bypasswater path, the flow rate in the bypass water path can be adjusted byfully opening, partially opening, or fully closing the valve. Byadjusting the flow rate in the bypass water path at the time when theapparatus for manufacturing sterilizing water is installed, themanufacturing conditions for the sterilizing water can be kept propereven if the raw water for producing the sterilizing water has varioussupply quantities or pressures.

If the vessel for overflow is provided in the sterilizing water tank,the pressure on the downstream side of the suction type feeder providedin the water path is stabilized, so that the feeding operation of thesuction type feeder is stabilized.

1. An apparatus for manufacturing sterilizing water, in whichsterilizing water is manufactured by mixing an acid solution consistingof hydrochloric acid or acetic acid or a mixture thereof and achlorine-based solution consisting of sodium hypochlorite or chlorinedioxide or a mixture thereof with water, comprising: a feeder providedwith a first flow path, in which said acid solution is fed to a part ofa water flow to produce a dilute acid solution, and a second flow path,in which said chlorine-based solution is fed to a remainder of saidwater flow to produce a dilute chlorine-based solution; and a mixerwhich is arranged on the downstream side of said first and second flowpaths to mix said dilute acid solution sent through said first flow pathwith said dilute chlorine-based solution sent through said second flowpath.
 2. The apparatus for manufacturing sterilizing water according toclaim 1, characterized in that said feeder is a feeder for feeding saidacid solution and said chlorine-based solution by suction utilizing anegative pressure produced in water flows in said first and second flowpaths, and feeding using a pump is not performed.
 3. The apparatus formanufacturing sterilizing water according to claim 1, characterized inthat said first and second flow paths are separated by a separationwall.
 4. An apparatus for manufacturing sterilizing water, in whichsterilizing water is manufactured by mixing an acid solution consistingof hydrochloric acid or acetic acid or a mixture thereof and achlorine-based solution consisting of sodium hypochlorite or chlorinedioxide or a mixture thereof with water, comprising: a feeder, which isprovided with a flow path for feeding said acid solution to a water flowto produce a dilute acid solution, for feeding said chlorine-basedsolution to said dilute acid solution; and a mixer which is arranged onthe downstream side of said feeder to mix said water flow.
 5. Theapparatus for manufacturing sterilizing water according to claim 4,characterized in that said feeder is a feeder for feeding said acidsolution and said chlorine-based solution by suction utilizing anegative pressure produced in the water flow, and feeding using a pumpis not performed.
 6. The apparatus for manufacturing sterilizing wateraccording to claim 1, characterized in that said feeder is provided witha movable portion that performs opening/closing operation of flow pathfor the water flow by the water supply pressure of water flow, and bysaid opening/closing operation, a check valve for feeding at leasteither of said acid solution and said chlorine-based solution is openedor closed.
 7. The apparatus for manufacturing sterilizing wateraccording to claim 1, characterized in that said mixer is a static mixerin which the water flow is mixed so as to be a substantially turbulentflow.
 8. The apparatus for manufacturing sterilizing water according toclaim 7, characterized in that said mixer is a mixer in which mixing isperformed in the water flow in a tube, and is a static mixer in which aplurality of mixing blades having different directions are arranged insaid tube along the lengthwise direction of said tube, and asubstantially turbulent flow is produced in the water flow in said tubeby each of said mixing blades, by which the water flow is mixed.
 9. Theapparatus for manufacturing sterilizing water according to claim 8,characterized in that said mixing blades are manufactured by twisting aflat plane shaped plate member in connecting portions with narrowwidths, which are provided on said plate member.
 10. The apparatus formanufacturing sterilizing water according to claim 1, characterized inthat the water flow is produced by a pump located on the upstream sideof said feeder.
 11. The apparatus for manufacturing sterilizing wateraccording to claim 1, characterized in that said chlorine-based solutionis sodium hypochlorite, and the pH of said sterilizing water is in therange of 4.8 to 7.5.
 12. An apparatus for manufacturing sterilizingwater, in which sterilizing water is manufactured by feeding an acidsolution consisting of hydrochloric acid or acetic acid or a mixturethereof and a chlorine-based solution consisting of sodium hypochloriteor chlorine dioxide or a mixture thereof to water, comprising: an acidsolution feeder for feeding said acid solution to a part of a water flowto produce a dilute acid solution; a dilute acid solution tank whichstores said dilute acid solution and releases the supply pressure of thepart of said water flow; a chlorine-based solution feeder for feedingsaid chlorine-based solution to a remainder of the water flow to producea dilute chlorine-based solution; a dilute chlorine-based solution tankwhich stores said dilute chlorine-based solution and releases the supplypressure of the remainder of said water flow; a suction water path whichhas two suction ports, and also has a joining portion for joining saiddilute acid solution and said dilute chlorine-based solution together bysucking said dilute acid solution in said dilute acid solution tank andsaid dilute chlorine-based solution in said dilute chlorine-basedsolution tank from said two suction ports; a pump which is connected tosaid suction water path to suck and discharge said dilute acid solutionand said dilute chlorine-based solution, which have been joinedtogether, via said suction water path; an acid solution mixer which isprovided at any position between said acid solution feeder and said pumpto mix said dilute acid solution; and a chlorine-based solution mixerwhich is provided at any position between said chlorine-based solutionfeeder and said pump to mix said dilute chlorine-based solution.
 13. Theapparatus for manufacturing sterilizing water according to claim 12,characterized in that said apparatus for manufacturing sterilizing waterfurther comprises: a raw water tank; and at least one raw water pump forsucking raw water from said raw water tank to produce the water flow,wherein said part of said water flow and said remainder of said waterflow are formed by said raw water pump.
 14. The apparatus formanufacturing sterilizing water according to claim 13, characterized inthat said raw water pump includes a first raw water pump for formingsaid part of said water flow to which said acid solution is fed and asecond raw water pump for forming said remainder of said water flow towhich said chlorine-based solution is fed.
 15. The apparatus formanufacturing sterilizing water according to claim 12, characterized inthat: said suction water path has water paths leading from each of saidtwo suction ports to said joining portion; said acid solution mixer isprovided in the water path between said suction port, through which thedilute acid solution is sucked from said dilute acid solution tank, andsaid joining portion; said chlorine-based solution mixer is provided inthe water path between said suction port, through which the dilutechlorine-based solution is sucked from said dilute chlorine-basedsolution tank, and said joining portion; and a joining mixer is furtherprovided between said joining portion and said pump.
 16. The apparatusfor manufacturing sterilizing water according to claim 12, characterizedin that said acid solution mixer is provided between said acid solutionfeeder and said dilute acid solution tank, and said chlorine-basedsolution mixer is provided between said chlorine-based solution feederand said dilute chlorine-based solution tank.
 17. An apparatus formanufacturing sterilizing water, in which sterilizing water ismanufactured by feeding an acid solution consisting of hydrochloric acidor acetic acid or a mixture thereof and a chlorine-based solutionconsisting of sodium hypochlorite or chlorine dioxide or a mixturethereof to water, comprising: an acid solution feeder for feeding saidacid solution to a water flow to produce a dilute acid solution; adilute acid solution tank which stores said dilute acid solution andreleases the supply pressure of part of said water flow; a pump forsucking said dilute acid solution from said dilute acid solution tank; achlorine-based solution feeder for feeding said chlorine-based solutionto the water flow from said dilute acid solution tank, which is producedby said pump; an acid solution mixer which is provided at any positionin a water path leading from said acid solution feeder to saidchlorine-based solution feeder to mix the dilute acid solution; and achlorine-based solution mixer which is provided at any position in awater path leading from said chlorine-based solution feeder to said pumpto mix the chlorine-based solution.
 18. The apparatus for manufacturingsterilizing water according to claim 17, characterized in that saidapparatus for manufacturing sterilizing water further comprises: a rawwater tank; a raw water pump for sucking raw water from said raw watertank to produce the water flow; and a sterilizing water tank for storingthe manufactured sterilizing water, wherein said part of said water flowand said remainder of said water flow are formed by said raw water pump.19. The apparatus for manufacturing sterilizing water according to claim17, characterized in that said acid solution mixer is provided betweensaid dilute acid solution tank and said chlorine-based solution feeder.20. The apparatus for manufacturing sterilizing water according to claim17, characterized in that said acid solution mixer is provided betweensaid acid solution feeder and said dilute acid solution tank.
 21. Anapparatus for manufacturing sterilizing water, in which sterilizingwater is manufactured by feeding an acid solution consisting ofhydrochloric acid or acetic acid or a mixture thereof and achlorine-based solution consisting of sodium hypochlorite or chlorinedioxide or a mixture thereof to water, comprising: an acid solutionfeeder for feeding said acid solution to part of water flow to produce adilute acid solution; an acid solution mixer provided on the downstreamside of said acid solution feeder; a chlorine-based solution feeder forfeeding said chlorine-based solution to the remainder of water flow toproduce a dilute chlorine-based solution; a chlorine-based solutionmixer provided on the downstream side of said chlorine-based solutionfeeder; a joining portion for joining said dilute acid solution sentfrom said acid solution mixer and said dilute chlorine-based solutionsent from said chlorine-based solution mixer together; a joining mixerfor mixing said dilute acid solution with said dilute chlorine-basedsolution at a position on the downstream side of said joining portion; apump for sucking and discharging a solution mixed on the downstream sideof said joining mixer; and a tank for storing sterilizing waterdischarged by said pump.
 22. An apparatus for manufacturing sterilizingwater, in which sterilizing water is manufactured by feeding an acidsolution consisting of hydrochloric acid or acetic acid or a mixturethereof and a chlorine-based solution consisting of sodium hypochloriteor chlorine dioxide or a mixture thereof to water, comprising: a rawwater tank; a raw water pump for sucking raw water from said raw watertank to produce a water flow; an acid solution feeder for feeding saidacid solution to said water flow to produce a dilute acid solution; achlorine-based solution feeder for further feeding said chlorine-basedsolution to said water flow; an acid solution mixer which is provided atany position in a water path leading from said acid solution feeder tosaid chlorine-based solution feeder to mix the dilute acid solution; achlorine-based solution mixer which is provided at any position on thedownstream side of said chlorine-based solution feeder to mix thechlorine-based solution; and a sterilizing water tank which is providedon the downstream side of said chlorine-based solution mixer to storethe manufactured sterilizing water.
 23. An apparatus for manufacturingsterilizing water, in which sterilizing water is manufactured by feedingan acid solution consisting of hydrochloric acid or acetic acid or amixture thereof and a chlorine-based solution consisting of sodiumhypochlorite or chlorine dioxide or a mixture thereof to water,comprising: a pump for discharging raw water to produce a water flow; anacid solution feeder for feeding said acid solution to part of saidwater flow to produce a dilute acid solution; an acid solution mixerprovided on the downstream side of said acid solution feeder; achlorine-based solution feeder for feeding said chlorine-based solutionto the remainder of said water flow to produce a dilute chlorine-basedsolution; a chlorine-based solution mixer provided on the downstreamside of said chlorine-based solution feeder; a joining portion forjoining said dilute acid solution sent from said acid solution mixer andsaid dilute chlorine-based solution sent from said chlorine-basedsolution mixer together; a joining mixer for mixing said dilute acidsolution with said dilute chlorine-based solution at a position on thedownstream side of said joining portion; and a tank for storingsterilizing water manufactured by joining.
 24. The apparatus formanufacturing sterilizing water according to claim 12, characterized inthat at least either of said acid solution feeder and saidchlorine-based solution feeder is a feeder for feeding said acidsolution or said chlorine-based solution by suction utilizing a negativepressure produced in the water flow, and feeding using a pump is notperformed.
 25. The apparatus for manufacturing sterilizing wateraccording to claim 12, characterized in that at least any one of saidacid solution mixer, said chlorine-based solution mixer, and saidjoining mixer is a static mixer for the water flow so as to produce asubstantially turbulent flow.
 26. A static mixer comprising a tubeserving as a water path; and many mixing elements provided in said tubeso as to be arranged in the direction of a flow in said tube,characterized in that: said mixing element has a joint for keeping anangular difference around the axis of said tube with respect to theadjacent mixing element; and said joint has a shape of polygon in crosssection so as to provide a flexible construction such that many mixingelements are arranged along the bend of tube, and when the arrangementdirection of mixing elements is bent, said mixing elements can followthe bent while said angular difference is kept.
 27. (canceled)
 28. Aregulator comprising: a turret portion which has a plurality of flowrate restricting orifices having different inside diameters, and iscapable of being turned to select any of said flow rate restrictingorifices; and a turret receiving portion which rotatably holds saidturret portion, and has a flow path aligning with any of said flow raterestricting orifices.
 29. The apparatus for manufacturing sterilizingwater according to claim 12, characterized in that the regulator asdescribed in claim 28 is inserted in at least either of the flow pathsfor said acid solution and said chlorine-based solution fed by eitherfeeder.
 30. A flow sensor comprising: a cylindrical piston member whichis made of a material having light transmitting properties, and moves inthe axial direction; a cylinder portion which movably holds said pistonmember with the axial direction of said piston member being directed inthe substantially vertical direction, has a cylindrical inside sidesurface, and is provided with a plurality of minute holes arranged insaid inside side surface so that said minute holes serve as a flow pathin succession according to the axial displacement of said piston member;a front chamber and a rear chamber which are separated from each otherby said cylinder portion and said piston member, and are connected toeach other by said minute holes; a light intercepting member which movestogether with said piston member; a light emitting element which emitseither light of ultraviolet rays, visible rays, and infrared rays, andis arranged so that a light path is formed in the range in which saidlight intercepting member moves with said light being used as detectionlight; and a light receiving element which is arranged to receive saidlight of said light emitting element so that it can be detected thatsaid light intercepting member is located in said light path,characterized in that said flow sensor is used in an orientation suchthat when said piston member moves downward due to the gravity, theminute holes are closed; when a differential pressure obtained byremoving the pressure of working fluid in said rear chamber from thepressure of working fluid in said front chamber is not higher than apredetermined working pressure, a movable member consisting of saidlight intercepting member and said piston member closes at least some ofsaid minute holes, and when said differential pressure becomes higherthan the predetermined working pressure, said movable member movesupward according to said differential pressure, and operates so as toopen the closed minute holes in succession to cause a large quantity ofworking fluid to flow from said front chamber to said rear chamber; anda change in the detected light quantity produced by the interception ofsaid light path caused by said light intercepting portion of saidmovable member moved by a change in said differential pressure isdetected by said light receiving element, and the flow rate of saidworking fluid is detected based on a change in the output signal. 31.The apparatus for manufacturing sterilizing water according to claim 12,characterized in that an electromagnetic valve capable of shutting offthe outflow of sterilizing water is further provided in at least eitherwater path; and said electromagnetic valve is controlled according tosaid output signal by using the flow sensor as described in claim 30 inthe flow path for the chemical fed by either feeder.
 32. An apparatusfor manufacturing sterilizing water, in which sterilizing water ismanufactured by feeding an acid solution consisting of hydrochloric acidor acetic acid or a mixture thereof and a chlorine-based solutionconsisting of sodium hypochlorite or chlorine dioxide or a mixturethereof to water, comprising: a first water path; a first feeder, whichis provided in said first water path, for feeding said acid solution; asecond water path, which is divided from said first water path at aposition on the upstream side of said first feeder and is returned tosaid first water path at a position on the downstream side of said firstfeeder; a second feeder, which is provided in said second water path,for feeding said chlorine-based solution; a first bypass water pathwhich is divided from said first water path and is returned to saidfirst water path to bypass said first feeder; a second bypass water pathwhich is divided from said second water path and is returned to saidsecond water path to bypass said second feeder; a first flow raterestricting valve provided in said first bypass water path; a secondflow rate restricting valve provided in said second bypass water path;and a sterilizing water tank for receiving a water flow in said firstwater path.
 33. An apparatus for manufacturing sterilizing water, inwhich sterilizing water is manufactured by feeding an acid solutionconsisting of hydrochloric acid or acetic acid or a mixture thereof anda chlorine-based solution consisting of sodium hypochlorite or chlorinedioxide or a mixture thereof to water, comprising: a main water path; afirst feeder, which is provided in said main water path, for feedingsaid acid solution to a water flow; a second feeder, which is providedin said main water flow so as to be located on the downstream side ofsaid first feeder, for feeding said chlorine-based solution; a firstbypass water path which is divided from said main water path and isreturned to said main water path to bypass said first feeder; a secondbypass water path which is divided from said main water path and isreturned to said main water path to bypass said second feeder; a firstflow rate restricting valve provided in said first bypass water path; asecond flow rate restricting valve provided in said second bypass waterpath; and a sterilizing water tank for receiving a water flow in saidmain water path.
 34. The apparatus for manufacturing sterilizing wateraccording to claim 18, characterized in that said sterilizing water tankhas a vessel having a certain overflow level; at least any of said waterpaths leading to said sterilizing water tank has an outflow portarranged below said overflow level in said vessel; and said sterilizingwater tank stores a fluid overflowing said vessel.